Easy Flank Steak and Mushroom Soup with Sour Cream and Cabbage Noodles

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This Easy Flank Steak and Mushroom Soup with Sour Cream and Cabbage Noodles is my kind of comfort food — hearty, earthy, and rich without being heavy. The juicy slices of seared flank steak add bold flavor, while the mushrooms and creamy broth give it that cozy, satisfying touch. It’s one of those recipes that looks impressive but comes together without too much effort, which makes it a win on busy weeknights or when you want something special but don’t want to overthink it.

I’ve always loved a good mushroom soup, but adding thinly sliced steak and a bed of buttery cabbage noodles completely transforms it. The sour cream swirl on top brings just the right amount of tang to balance out the richness. If you’ve never tried cabbage in place of noodles, this might just be your gateway. It’s not just delicious — it’s smart comfort food that’s lower in carbs and absolutely packed with flavor.

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Why You’ll Love This Easy Flank Steak and Mushroom Soup with Sour Cream and Cabbage Noodles

• It’s deeply flavorful and satisfying — thanks to the umami-packed mushrooms and seared steak.
• A great low-carb alternative to traditional noodle soups.
• Comes together quickly and feels like something you’d get in a cozy European bistro.
• Perfect for meal prep — it actually tastes even better the next day.
• That creamy, tangy finish from the sour cream takes it over the top.
• A single pot brings everything together: less mess, more magic.

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What Kind of Steak Should I Use for Easy Flank Steak and Mushroom Soup?

Flank steak is my go-to for this recipe because it’s lean, flavorful, and quick to cook. When sliced thinly against the grain, it stays tender and works beautifully in soups. However, if you can’t find flank steak, skirt steak or sirloin are excellent alternatives. You want a cut that sears well and doesn’t get too chewy when added back into the hot broth.

Just make sure not to overcook it — a quick sear and rest before slicing is key to keeping it tender. I prefer to cook the steak separately and add it toward the end so it retains its juiciness without stewing too long.

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Options for Substitutions

This soup is flexible, and I often tweak it depending on what I have in the fridge. If you’re not into beef, you can swap the flank steak for:

• Chicken thighs or breast – seared and shredded or sliced.
• Ground beef – browned and added directly into the broth.
• Tofu or tempeh – for a vegetarian option with texture and protein.

Not into cabbage? Try:

• Zucchini noodles (zoodles) for a light and fresh twist.
• Cauliflower rice to keep it low-carb and grain-free.
• Egg noodles or spaetzle if you’re after something more traditional and hearty.

For the creamy touch, full-fat Greek yogurt is a great stand-in for sour cream if you’re looking for a lighter or protein-boosted version. And while cremini mushrooms are my favorite here, white button, shiitake, or even a mix of wild mushrooms can elevate the flavor even more.

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Ingredients for This Easy Flank Steak and Mushroom Soup with Sour Cream and Cabbage Noodles

• Flank Steak
  The star protein of this dish — seared for flavor, then thinly sliced to melt into the soup with every bite.
• Mushrooms
  They bring earthy depth and richness to the broth. I love using cremini or baby bella mushrooms, but any variety works.
• Onion
  Sautéed until soft, it lays the aromatic foundation of the soup and enhances the savory notes.
• Garlic
  A few cloves go a long way to brighten and deepen the flavor of the broth.
• Beef Broth
  This is your soup’s base — hearty and rich. Choose low-sodium if you want more control over salt levels.
• Heavy Cream
  Adds luscious creaminess and brings the soup to a luxurious consistency without feeling too heavy.
• Butter
  Used for sautéing, it adds a bit of richness and helps develop flavor when cooking the mushrooms and onions.
• Olive Oil
  Great for searing the steak and getting a nice golden crust without smoking up the kitchen.
• Cabbage
  Thinly sliced and gently cooked down, cabbage becomes tender and makes a perfect noodle substitute.
• Sour Cream
  A cool, tangy contrast to the warm, creamy soup — dolloped on top right before serving.
• Fresh Parsley
  A touch of green at the end for freshness and color.
• Salt & Pepper
  Essential for seasoning each layer of flavor — don’t forget to season the steak separately!

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Step 1: Sear the Flank Steak

Start by patting the flank steak dry and seasoning it generously with salt and pepper. Heat a skillet over medium-high heat with a drizzle of olive oil. Once hot, sear the steak for about 3–4 minutes per side until a golden crust forms. Remove from heat, let it rest for 10 minutes, then slice it thinly against the grain. Set aside.

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Step 2: Sauté the Aromatics

In a large pot or Dutch oven, melt butter over medium heat. Add the diced onion and cook until soft and translucent, about 5 minutes. Stir in the minced garlic and cook for another 30 seconds, just until fragrant.

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Step 3: Cook the Mushrooms

Add the sliced mushrooms to the pot and season lightly with salt. Sauté for 6–8 minutes until they release their moisture and start to brown. Don’t rush this part — browned mushrooms mean maximum flavor.

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Step 4: Build the Broth

Pour in the beef broth, scraping the bottom of the pot to lift any flavorful bits. Bring to a simmer and let it bubble gently for 10–15 minutes to deepen the flavor.

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Step 5: Stir in the Cream

Lower the heat and stir in the heavy cream. Simmer for another 5 minutes, letting the soup thicken slightly. Taste and adjust seasoning with salt and pepper if needed.

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Step 6: Cook the Cabbage Noodles

In a separate pan, sauté the shredded cabbage in a bit of butter until tender and lightly golden — about 7–10 minutes. Season with a pinch of salt and set aside.

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Step 7: Add the Steak

Just before serving, stir the sliced flank steak into the soup to warm it through. Don’t boil it — just let it heat gently so it stays juicy and tender.

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Step 8: Assemble and Serve

Spoon a portion of sautéed cabbage into each bowl, ladle the hot soup over the top, and finish with a generous dollop of sour cream. Sprinkle with chopped parsley for a fresh, vibrant touch.

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How Long to Cook the Easy Flank Steak and Mushroom Soup with Sour Cream and Cabbage Noodles

The total cooking time for this dish is about 40 to 45 minutes:

• Searing the steak: 8–10 minutes including resting time
• Sautéing aromatics and mushrooms: 10–12 minutes
• Simmering the broth and cream: 15–20 minutes
• Cooking the cabbage noodles: 7–10 minutes

Since the steak is cooked first and only added back at the end, you’re never overcooking it — just gently warming it through.

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Tips for Perfect Easy Flank Steak and Mushroom Soup

• Slice flank steak against the grain to keep it tender and easy to chew.
• Don’t overcrowd the mushrooms while sautéing — cook in batches if needed so they brown instead of steam.
• Use low-sodium beef broth so you can control the seasoning as the soup reduces.
• Rest the steak before slicing to keep the juices in and the meat moist.
• Add the cream at a gentle simmer, not a boil, to prevent it from curdling or separating.
• Cook cabbage until just tender, not mushy, so it still holds its noodle-like texture.
• Serve immediately after combining everything for the freshest flavors and texture.

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Watch Out for These Mistakes While Cooking

• Overcooking the Flank Steak
  Flank steak is lean and can become tough if left on heat too long. Just a quick sear and a gentle reheat in the soup is all it needs.
• Boiling the Soup After Adding Cream
  A rolling boil can cause the cream to split or curdle. Always reduce to a simmer before adding dairy.
• Slicing Cabbage Too Thick
  Thick strips of cabbage won’t cook evenly and can feel heavy. Aim for thin, noodle-like shreds for the best texture.
• Skipping the Rest Time for Steak
  Let the steak rest at least 10 minutes before slicing to lock in juices — cutting too soon will dry it out.
• Not Deglazing the Pot
  After sautéing mushrooms and aromatics, make sure to scrape up all those golden brown bits when you add broth — that’s where the flavor lives.
• Using Mushrooms Straight from the Package
  Mushrooms should be wiped clean and sliced evenly — wet mushrooms won’t brown properly.

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What to Serve With Easy Flank Steak and Mushroom Soup with Sour Cream and Cabbage Noodles?

Crusty Sourdough Bread

Perfect for soaking up the creamy broth and adding a little crunch.

Simple Arugula Salad

A peppery salad dressed with lemon and olive oil balances out the richness of the soup.

Roasted Garlic Green Beans

Add a garlicky veggie side with snap and freshness.

Crispy Potato Pancakes

Savory and golden, these pair beautifully with the soup’s creamy texture.

Aged Cheese Plate

A small selection of cheeses makes this meal feel extra special.

A Glass of Red Wine

Try a light Pinot Noir or a dry Cabernet — both complement the earthy mushrooms and steak.

Garlic Flatbread

Easy to make or buy, and ideal for scooping up every drop of soup.

Pickled Vegetables

A tangy side dish that cuts through the creaminess and refreshes the palate.

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Storage Instructions

This soup holds up really well, making it a great option for leftovers or meal prep. Here’s how to store it safely and deliciously:

• Refrigerator: Store the soup (without sour cream or cabbage) in an airtight container for up to 4 days. Keep the sautéed cabbage and sour cream separate for best texture and freshness.
• Freezer: The soup base (minus the cabbage and sour cream) freezes beautifully for up to 2 months. Let it cool completely before transferring to freezer-safe containers. Thaw overnight in the fridge and reheat gently on the stovetop.
• Reheating: Warm on the stove over low heat until hot. Add a splash of broth or cream if it thickens too much. Stir in fresh cabbage noodles and top with sour cream when ready to serve.

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Estimated Nutrition (Per Serving – Based on 4 Servings)

• Calories: ~420
• Protein: 28g
• Fat: 29g
• Saturated Fat: 13g
• Carbohydrates: 11g
• Fiber: 3g
• Sugar: 5g
• Cholesterol: 95mg
• Sodium: 680mg

Note: Nutrition will vary slightly depending on exact brands and substitutions used.

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Frequently Asked Questions

What cut of steak can I use instead of flank?

If flank steak isn’t available, skirt steak, sirloin, or even thinly sliced ribeye work well. Just make sure to sear quickly and slice thinly against the grain.

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Can I make this soup ahead of time?

Yes! In fact, the flavors deepen after a day in the fridge. Just store the cabbage and sour cream separately and reheat the soup gently before serving.

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Is this soup keto or low-carb?

Yes — especially if you keep the cabbage noodles and avoid traditional pasta. It’s naturally low in carbs and high in protein.

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Can I use a different type of mushroom?

Absolutely. Cremini, button, shiitake, or even a wild mushroom blend all bring wonderful depth. Mix and match for extra umami.

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What’s the best way to cut cabbage into noodles?

Slice the cabbage in half, remove the core, then use a sharp knife to cut thin, long strips — think fettuccine-width for the best results.

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Can I make this soup dairy-free?

Yes, swap the heavy cream for full-fat coconut milk and use a plant-based sour cream or omit it entirely. The flavor will still be rich and cozy.

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How can I make the soup thicker?

Simmer it a little longer uncovered to reduce the liquid, or add a spoonful of cream cheese or a cornstarch slurry to thicken without changing the flavor too much.

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Is this soup freezer-friendly?

Yes, but freeze the soup base only. Leave out the cabbage and sour cream, and add those fresh when reheating for the best taste and texture.

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Conclusion

This Easy Flank Steak and Mushroom Soup with Sour Cream and Cabbage Noodles is one of those recipes that checks all the boxes: quick, comforting, flavorful, and just a little bit unexpected. It transforms simple ingredients into a cozy bowl of something really special — rich with umami from mushrooms, creamy with a swirl of sour cream, and grounded with tender strips of steak. Whether you’re cooking for a chilly night, meal prepping for the week, or just craving something hearty without being heavy, this soup has you covered. It’s easy to love, easy to customize, and definitely worth making again and again.

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