For the sweet and spicy sauce:
2 tablespoons soy sauce or tamari
1 tablespoon rice or white wine vinegar
2 cloves garlic, smashed and minced
1" freshly grated ginger root
1 tablespoon honey
For the stir-fry:
8 ounces tempeh, cut into 1" cubes
1 green bell pepper, cored, seeded and sliced
1 white onion, cut into slivers
3-4 green onions, sliced
1 tablespoon vegetable oil
Make the sauce: Whisk all sauce ingredients together in a non-reactive bowl and set aside.
Heat a skillet or wok to medium-high on the stove top. Add oil. When oil is shimmering, add tempeh pieces and cook for 8-10 minutes, flipping the tempeh pieces with kitchen tongs every 2 minutes so that the tempeh browns on all sides. Add bell pepper and white onion and cook for 2 more minutes. Add sauce and cook for one more minute. Garnish with green onions and serve immediately.