2 cups thinly sliced shiitake mushrooms (about ½ pound)
1 cup sliced onion
1 cup bell pepper strips
4 cups sliced bok choy (about 1 medium head)
Instructions
Combine ginger, garlic, soy sauce, oil, and crushed red pepper (optional) in a large zip-top bag; add steak to bag. Seal and marinate in refrigerator 20 minutes.