1. Preheat the oven to 375°F and lightly grease a large baking dish.

2. Heat olive oil in a large skillet over medium heat. Add diced onion and cook until softened and translucent.

3. Add ground beef to the skillet and cook until fully browned, breaking it apart as it cooks. Drain excess grease if necessary.

4. Stir in minced garlic and cook for about 1 minute until fragrant.

5. Add taco seasoning and water to the beef mixture. Stir well and allow the mixture to simmer for several minutes so the flavors fully combine.

6. Mix in cooked rice, refried beans, and black beans. Stir until the filling becomes thick, creamy, and evenly combined.

7. Spread a thin layer of enchilada sauce across the bottom of the prepared baking dish.

8. Warm the tortillas slightly to make them easier to roll.

9. Spoon the beef mixture into the center of each tortilla. Add a little shredded cheese inside each burrito if desired.

10. Fold the sides inward and roll each tortilla tightly into a burrito shape.

11. Arrange the burritos seam-side down in the baking dish.

12. Pour the remaining enchilada sauce evenly over the burritos.

13. Sprinkle cheddar cheese and Monterey Jack cheese generously over the top.

14. Bake uncovered for 20 to 25 minutes until the cheese is melted, bubbly, and lightly golden.

15. Remove from the oven and let the burritos rest for 5 minutes before serving.

16. Garnish with sour cream, sliced jalapeños, and fresh cilantro before serving.