Combine the ingredients for the marinade in a bowl. Add pepper steak and mix thoroughly. Let marinate for 20 minutes.

Heat a wok and two tablespoons olive oil. Sauté onions on medium heat until transparent; then add peppers and sauté over high heat for two to three minutes. Pour onions and peppers into a large bowl.

Stir-fry all the mushrooms for approximately three minutes, until soft and fragrant. (Add more oil as needed.) Add shredded bok choy, and cook 30 seconds longer. Pour mushrooms and bok choy into the bowl with the sautéed peppers.

Place meat and marinade in the wok and stir-fry meat until cooked through, about four to five minutes.

Add cooked vegetables back into wok and toss thoroughly. Serve warm on a bed of rice, sprinkled with kosher salt and freshly ground black pepper.