Kohlrabi and Beef Stir-Fry

Ingredients:
1/2 cup sliced onion
2 cups peeled and chunked kohlrabi
1/2 cup sliced fresh mushrooms
2 tbsp chopped fresh parsley
2 tbsp butter
1 1/2 tbsp bottled oyster sauce
12 oz. broiled lean beef sirloin steak, cut into strips
2 cups cooked vermicelli

Direction:
1. Coat a large nonstick skillet with nonstick cooking spray. Preheat over medium; add onion and saute for 2 minutes.
2. Add kohlrabi, mushrooms, parsley, butter and oyster sauce.
3. Cover and cook over medium heat about 5 minutes.
4. Add beef and vermicelli to skillet and cook, tossing frequently, until meat is heated through. Season with black pepper to taste.