Dinner · Part 3 of 3: Tips & recipe card

Slow Cooker Sour Cream Stroganoff Flank Steak Tips, FAQ & printable recipe

Name: Slow Cooker Sour Cream Stroganoff Flank Steak
Prep time: 15 min
Cook time: 8 h
Total time: 8 h 25 min
Cuisine: American
Ingredients: 2 lb flank steak, thinly sliced against the grain; 1 cup peeled pearl onions; 2 cups crinkle-cut carrots; 1 cup sour cream; 1 oz brown gravy mix (1 packet); 12 oz wide egg noodles; 2 tbsp butter, for the noodles

By Clara Weller · Oct 28, 2026

Slow cooker full of creamy stroganoff with flank steak, pearl onions, and carrots

Prep: 15 min
Cook: 8 h
Total: 8 h 25 min
Serves: 6

Includes 10 min resting

Tips for success

For the most tender beef, slice the flank steak against the grain — that means cutting perpendicular to the lines of muscle fiber.

If the steak is very thick, you can also cut it into 2-inch pieces and let them shred naturally during cooking. The slow cooker will break down the meat, so even slightly thicker strips will become tender.

To make the sauce extra velvety, stir in a few tablespoons of cold butter just before serving. This is optional but adds a luxurious shine and richness.

If the sauce seems too thin, mix a tablespoon of cornstarch with a little cold water and stir it into the slow cooker, then let it cook for 15 more minutes on high.

Variations

Mushroom Stroganoff: Add 8 oz sliced cremini mushrooms with the onions and carrots. Sauté them first in a little butter until browned for extra flavor, or add them raw — they will cook down in the slow cooker.
Chicken Stroganoff: Replace the flank steak with 2 lb boneless, skinless chicken thighs. Cook on low for 6-7 hours until the chicken is tender and reaches 165°F (74°C). Shred or slice before serving.
Low-Carb Version: Skip the noodles and serve the stroganoff over cauliflower rice or steamed broccoli. The beef and sauce are naturally low-carb and satisfying on their own.
Spicy Stroganoff: Add 1/2 teaspoon smoked paprika and 1/4 teaspoon cayenne pepper to the gravy mix for a subtle kick. A splash of Worcestershire sauce also adds depth, if you have it.

Storage and make-ahead

Fridge: Keep leftovers in an airtight container for up to 4 days. Reheat gently on the stovetop or in the microwave, adding a splash of broth to loosen the sauce.
Freezer: Freeze the beef and sauce (without noodles) in a freezer-safe container for up to 3 months. Thaw overnight in the refrigerator and reheat gently.
Reheat: Reheat individual portions in the microwave for 2-3 minutes, stirring halfway.

Store leftovers in an airtight container in the refrigerator for up to 4 days. The sauce will thicken as it cools; add a splash of beef broth or water when reheating to loosen it. The noodles are best stored separately to avoid becoming mushy.

This recipe is perfect for making ahead. Assemble the slow cooker insert the night before, cover, and refrigerate. In the morning, place the insert in the slow cooker and cook as directed.

You can also cook the entire dish and refrigerate it for up to 3 days; reheat gently on the stovetop or in the microwave.

Serving ideas

Serve the stroganoff over wide egg noodles, which are traditional and hold up well to the thick sauce. You can also use mashed potatoes, rice, or crusty bread. For a fresh contrast, add a simple green salad with a vinaigrette or steamed green beans on the side.

When plating, use a slotted spoon to lift the beef and vegetables, then ladle the gravy over the top.

This ensures each serving gets a good amount of sauce without drowning the noodles. Garnish with a sprinkle of fresh parsley if you like, though the video does not show it.

Frequently asked questions

Can the beef be cooked on high instead of low?

Yes, cook on high for 4 hours instead of low for 8 hours. The beef will be tender, but the sauce may not reduce as much. If the sauce is thin, remove the beef and vegetables, then simmer the sauce on the stovetop or cook on high with the lid off for 15-20 minutes to thicken.

Why does the sour cream sometimes curdle?

Curdling can happen if the slow cooker is on high and the sour cream is added too early or if the heat is too intense. To prevent this, use full-fat sour cream, cook on low, and avoid stirring during cooking. If curdling occurs, the sauce may look grainy but will still taste fine; blending it briefly can smooth it out.

Can this recipe be made without a slow cooker?

Yes, use a heavy Dutch oven and cook in a 300°F (150°C) oven for 3-4 hours, or simmer on the stovetop over very low heat for 2-3 hours, until the beef is fork-tender. Check occasionally and add a little beef broth if needed.

What is the best way to slice flank steak for this dish?

Flank steak is a lean cut with distinct grain. Slice it thinly against the grain, meaning perpendicular to the lines of muscle fiber. This shortens the muscle fibers, making the meat more tender. If the steak is partially frozen, it is easier to slice very thin.

Can the leftovers be frozen with the noodles?

It is best to freeze the beef and sauce without the noodles, as noodles become mushy when frozen and reheated. Store the noodles separately in the refrigerator and reheat them briefly, or cook fresh noodles when serving the leftovers.

Recipe card

Slow Cooker Sour Cream Stroganoff Flank Steak

Prep 15 minCook 8 hRest 10 minTotal 8 h 25 minServes 6

Ingredients

2 lb flank steak, thinly sliced against the grain
1 cup peeled pearl onions
2 cups crinkle-cut carrots
1 cup sour cream
1 oz brown gravy mix (1 packet)
12 oz wide egg noodles
2 tbsp butter, for the noodles

Instructions

Place the sliced flank steak strips in the bottom of the slow cooker. Scatter the pearl onions and crinkle-cut carrots over the beef. Spoon the sour cream over the top, then sprinkle the brown gravy mix evenly over everything. Do not stir.
Cover the slow cooker and cook on low for 8 hours, or on high for 4 hours, until the beef is fork-tender. The sauce will darken and become velvety as the sour cream and gravy meld. Let it rest for 3 minutes before slicing.
About 20 minutes before serving, bring a large pot of salted water to a boil. Cook the egg noodles according to package directions until al dente. Drain and toss with the butter until melted.
Once the beef is fork-tender, turn off the slow cooker and let the beef rest in the sauce for at least 10 minutes. This allows the juices to redistribute and the sauce to thicken slightly.
Divide the buttered noodles among warm plates. Ladle the beef, onions, carrots, and creamy gravy over the top. Serve immediately.

Contains: gluten, milk, eggs

Estimated nutrition per serving

Calories: 520
Protein: 35 g
Carbohydrates: 45 g
Fat: 22 g

Automatic estimate from the ingredient list, not laboratory-verified.

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This recipe is based on a short cooking video and is published under the pen name Clara Weller. It was checked before publication, but errors can slip through. Nutrition, when shown, is an estimate. Read more in our editorial policy and on our food safety page.