In a small bowl, combine tomato, about 1 Tbsp of the onion, peppers, and garlic, a dash of salt, a sprinkle of cilantro, and a twist of fresh lemon or lime juice. Set aside. Heat oven to 375 F, then heat oil in a large skillet over medium heat. Add the remaining onion, garlic, and peppers to the skillet. Cook until the onion begins to turn clear. Add the cumin, chili powder, and salt, then the can of refried beans and a squeeze of fresh lemon or lime juice. Stir over medium heat until warmed through. Remove from heat and cover to keep warm. Once the oven is preheated, spread some of the bean mixture onto each tortilla, then add some of the fresh salsa, and a handful of the grated cheese. Roll up each tortilla and place on a baking sheet in the oven. Heat until burritos are heated through and just starting to crisp. Garnish with sour cream, cilantro, and fresh diced avocado.