Ingredients
Method
- Heat one tablespoon of butter in a heavy-bottomed skillet over medium-high heat until bubbling.
- Pat beef strips dry with paper towels, season with salt and pepper, and sear in a single layer for two minutes per side until deeply browned.
- Remove beef from the skillet and set aside on a warm plate.
- Add remaining butter to the same skillet, then sauté the mushrooms until golden brown.
- Add the diced onion to the mushrooms and cook until translucent, then add garlic and cook for one minute.
- Sprinkle flour over the vegetable mixture and stir for one minute to cook off the raw flour taste.
- Gradually whisk in the beef stock, scraping up any browned bits from the bottom of the pan.
- Simmer the sauce until it thickens, then reduce heat to low and stir in the sour cream and fresh thyme.
- Return the beef and any accumulated juices back into the skillet and heat through until warm, being careful not to boil the sauce.
- Serve immediately over warm noodles or mashed potatoes.
Notes
Always cut the beef against the grain to ensure maximum tenderness. For the best consistency, ensure the sour cream is at room temperature before adding to the sauce to prevent curdling. Do not let the sauce come to a boil once the sour cream is added.