Preparation / Directions:
1. Combine beef, lemon juice, Worcestershire sauce, salt and pepper in heavy-duty food storage bag; seal. Refrigerate 2 hours.
2. Heat 1 T oil in large skillet over med-high heat. Add onion; saut‚' until golden brown, 3-5 min. Add mushrooms; saut‚ until softened, 3-5 min. Remove to bowl; keep warm.
3. Increase heat to high; heat remaining oil in same skillet. Add beef; saut‚' 2 min. Reduce heat to low; stir in onions and mushrooms.
4. Whisk broth, flour and tomato paste in bowl until smooth. Stir into skillet. Cook, stirring, until slightly thickened and bubbly, 2 min.
5. Stir in sour cream; don't boil. Serve over noodles; top with o