In a small bowl, whisk the sauce ingredients together and set aside.
Preheat a wok or large skillet with oil over medium heat. Add in the sliced bell pepper and cook until golden brown (about 3 minutes). Remove the peppers from the pan and set them aside.
Turn the heat up to high and add the beef strips to the pan. Cook the beef until it's golden brown.
Add the bell peppers back to the pan. Pour the sauce over the steak and veggies. Cook for an additional 2-4 minutes.
Remove from heat and enjoy alongside your favorite grain or noodle!