Fettucine with Mushroom Sauce

From Sandra Lee's 'Semi-Homemade' 20-minute meals

2 packages (9oz) refrigerated fettucini
3 T extra-virgin olive oil
2 packages (8oz) pre-sliced mushrooms
1 cup frozen or fresh chopped onions
1 1/2 c reduced-sodium beef broth
1/3 c dry sherry
1/4 c balsamic vinegar
1 packet (1.5oz) beef stew seasoning
1 can (14.5oz) diced tomato (with onion ad garlic) drained
Flat leaf parsely, chopped (optional)

1. In a large pot of boiling, salted water cook pasta according to package. Drain well and return to hot pot. Cover, keep warm.

2. Meanwhile, in a large skillet heat olive oil over medium-high heat. Add mushrooms and onions to hot oil. Cook and stir for 7 to 8 minutes.

3. Create a well in the center of the musroom mixture. Add beef broth, sherry and balsamic vinegar. Stir in beef stew seasoning until dissolved. Add drained tomatoes. Bring to boil;reduce heat. Simmer for 5 to 6 minutes.

4. Garnish with parsley, serve hot over cooked pasta.