Dice tofu. Heat oil until hot. Add tofu, garlic, and onions. Saute until onions are translucent, about 5 minutes. Add peppers and cook another 10 minutes or until most of the liquid is evaporated. Stir in tomato paste, chili powder, cumin, and salt. Stir well. Let cook 3 minutes or until heated through. Remove from heat and stir in lime juice and cilantro. Fill tortillas with tofu mixture. Top with cheese, if using. Roll up. Top with avocado and sour cream if using.