Heat the olive oil in a large skillet over medium-high heat. Add the steak strips in batches, season with salt and pepper, and cook until browned on all sides, about 3 minutes. Remove the steak from the skillet and set aside.
Step 2: Cook the Vegetables
Add the onions, garlic, and mushrooms to the skillet and cook until the onions are softened and the mushrooms are golden, about 5 minutes.
Step 3: Add the Remaining Ingredients
Add the beef broth, tomato paste, Worcestershire sauce, thyme, and Dijon mustard to the skillet. Bring to a simmer and cook for 5 minutes.
Step 4: Finish the Sauce
Add the steak back to the skillet and stir in the sour cream. Simmer for 5 minutes, stirring occasionally, until the sauce is thickened and the steak is cooked through. Season with salt and pepper to taste.
Closing Message
Beef Stroganoff is a classic dish that's easy to make and full of flavor. With just a few simple ingredients and a few minutes of cooking, you can enjoy a delicious meal that's sure to please the whole family.
