In a large skillet over medium heat, add the ground beef, diced onion, and minced garlic. Cook until the beef is browned and the onion is translucent, about 5-7 minutes. Drain excess fat if necessary.

Stir in the chili powder, cumin, paprika, salt, and black pepper. Cook for another 2 minutes until the spices are fragrant.

Add the black beans, corn, and cooked rice to the skillet. Mix well and cook for an additional 3-4 minutes until heated through.

Lay out the flour tortillas on a clean surface. Spoon an equal amount of the beef mixture onto the center of each tortilla, then sprinkle with shredded cheddar cheese.

Fold in the sides of the tortilla, then roll from the bottom up to enclose the filling completely.

Preheat a non-stick skillet over medium heat. Place the burritos seam-side down in the skillet and cook for 2-3 minutes on each side until golden brown and crispy.

Serve warm with salsa and sour cream on the side. Garnish with fresh cilantro if desired.