Roast beef is the ultimate convenience food when used as the spring board for the next-day meal! This stroganoff is absolutely AMAZING when made with tender bites of leftover medium-rare Prime Rib Roast! Your dinner's all ready as soon as the noodles are cooked!
Cook noodles according to package directions.
Meanwhile, stir-fry onion, garlic, mushrooms and thyme with a splash of vegetable oil in a deep skillet over medium-high heat, until softened and any liquid from the mushrooms has evaporated (4 to 5 minutes). Stir in wine and simmer until reduced by half. Stir in beef broth and bring to a simmer.
Mix sour cream and flour until smooth; gradually whisk into broth mixture. Stir and heat until sauce thickens. Add beef and heat through; season to taste.
Serve over hot egg noodles; garnish with minced fresh parsley.