Place a large deep-sided skillet over medium-high heat. Add the oil, and once hot, add the bell peppers and onion. Cook for 5 minutes until softened. Add the garlic, stir, and cook for 1 minute.
Add the black beans, cilantro, cumin, salt, and pepper, and stir to combine. Cook for 1-2 minutes. Pour in the lime juice and simmer until the liquid is cooked down. Remove from the heat and set aside.
Assemble the burritos by adding 1/2 cup of cooked rice to the center of each tortilla and forming it into a flat rectangle. Add half of the bean mixture, avocado slices, and cheese to each burrito. Fold in the side and then wrap tightly.
If desired, toast the burritos in a panini press or in a hot, dry skillet until golden brown and crispy on the outside.
Serve warm with your favorite sides or salsa.
Notes
This recipe can easily be doubled to use 1 can of black beans. If you want to prep ahead, make the black bean mixture and then refrigerate it for later. Reheat the beans and assemble the burritos.