Slow Cooker Sour Cream Stroganoff Flank Steak Step-by-step instructions

Before you start

Before you start, slice the flank steak against the grain into strips about 1/4-inch thick. If the steak is partially frozen, it is easier to slice. Peel the pearl onions if they are not already peeled — you can use frozen pearl onions to save time.

Measure the sour cream and have the gravy mix packet ready. Cook the egg noodles just before serving, so they are hot and fresh. No other prep is needed; the slow cooker does the rest.

Instructions

Layer and Cook

1. 1Layer the Ingredients
   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.
   Look for The beef, onions, and carrots are stacked in layers, with sour cream and gravy mix on top.
   Tip Keeping the gravy mix on top helps it dissolve into the sauce as the slow cooker heats.
2. 2Cook Low and Slow
   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.
   Look for The sauce is bubbling gently around the edges and the beef shreds easily with a fork.
   Safe temperature 145°F (63°C) internal temperature (steaks, chops and roasts)
   Tip Do not lift the lid during cooking — each peek adds 20 minutes to the cook time.

At the end of this phase, the slow cooker is filled with raw beef, onions, carrots, sour cream, and gravy mix. The sour cream and gravy mix form a thick paste on top.

As the slow cooker heats, you will hear a gentle bubbling and see the sauce begin to darken and thin. The beef will release juices, creating a rich liquid that will eventually become the gravy.

Rest and Prepare Noodles

3. 3Cook the Noodles
   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.
   Look for The noodles are tender but still firm to the bite, glistening with butter.
   Tip Reserve a cup of pasta water in case you want to loosen the sauce later.
4. 4Rest the Beef
   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.
   Look for The sauce has settled and no longer bubbles; the beef is moist and tender.
   Safe temperature 145°F (63°C) internal temperature (steaks, chops and roasts)
   Tip Resting is essential for whole-cut meats — it keeps the strips juicy.

The beef is fork-tender and the sauce is a deep mahogany color. The onions are translucent and the carrots are tender. The sauce has thickened to a velvety consistency. The noodles are cooked, drained, and tossed with butter, ready to be topped. The kitchen smells of rich beef and caramelized onions.

Serve

5. 5Serve Over Noodles
   Divide the buttered noodles among warm plates. Ladle the beef, onions, carrots, and creamy gravy over the top. Serve immediately.
   Look for Each plate gets a generous scoop of beef and vegetables in glossy gravy.
   Tip Warm the plates in a low oven for a few minutes to keep everything hot.

The final dish is a generous scoop of beef, onions, and carrots in glossy, creamy gravy, served over a bed of buttered egg noodles. The beef is moist and tender, the sauce is rich and savory with a hint of tang from the sour cream. Every element is hot and ready to eat.

Common mistakes

The most common mistake is lifting the lid to check on the food — this lets out heat and adds time. Another is using low-fat sour cream, which can separate and become grainy.

Also, do not stir the ingredients at the beginning; the gravy mix needs to dissolve slowly. Finally, do not overcook the noodles — they should be al dente because they will soften further when the hot sauce is spooned over them.

How to tell it’s done

The beef is done when it is fork-tender, meaning a fork can easily shred or cut through the strips. The sauce should be thick enough to coat the back of a spoon, and the onions and carrots should be soft but not mushy.

The internal temperature of the beef should reach at least 145°F (63°C) for food safety, but because it cooks for so long, it will be well above that and very tender.

• Steaks, chops and roasts: 145°F (63°C) in the thickest part, then a 3-minute rest