Heat olive oil in a large skillet over medium heat. Add the yellow onion and red bell pepper and cook, stirring occasionally, until softened, about 6 minutes.
Add garlic and ginger and stir 30 seconds or until fragrant.
Add the tempeh and cook, stirring occasionally, until lightly browned, about 5 minutes.
Add the soy sauce, lime juice, and green onions and stir to combine. Remove from the heat.
Place about 2 tablespoons each of shredded carrots and cabbage in each lettuce leaf. Scoop large spoonfuls of the tempeh mixture on top and sprinkle with chopped peanuts, fresh cilantro, extra green onions, and sriracha if desired.