This recipe can be revised to include broccoli or sugar snap peas in place of the green peppers. Fermented black beans can be found in Chinese food stores or online.
For the sauce, mix the first five ingredients together and set aside.
Heat 1 tablespoon of olive oil in a wok on medium high heat. (A large frying pan will do, preferably non-stick.) Add the sugar and salt and stir fry until no longer pink, about 3 minutes. Remove beef from wok and set aside.
Add the other tablespoon of olive oil to the wok. When hot, add the green peppers, mushrooms, garlic and fermented black beans and stir until peppers and mushrooms are crisp tender, about 3-4 minutes.
Return the beef to the wok. Give the sauce mixture a good stir to ensure the cornstarch is fully mixed, then add to wok and stir constantly until mixture thickens, about 2-3 minutes.
Serve over rice.
This recipe pairs nicely with Ginger-Garlic Jasmine Rice, which can be found in My Recipes.