1 lb. sirloin steak, slightly frozen
1 lg. onion, cut in wedges
1 sm. red pepper, cut in strips
1 med. zucchini, cut in 1/4" thick slices
1/2 tsp. dried tarragon leaves, crushed
1 jar (6 oz.) whole mushrooms, drained
1/2 c. beef broth
2 tbsp. Dijon mustard
1 c. sour cream
Hot cooked spaghetti squash