In a large mixing bowl, combine the cooked rice, black beans, fresh corn, diced tomatoes, sliced avocado, shredded cheese, chopped cilantro, lime juice, salt, and black pepper. Mix well until all ingredients are evenly distributed.

Assemble the Burritos

Lay a large flour tortilla flat on a clean surface. Spoon a generous amount of the filling mixture onto the center of the tortilla. Fold in the sides and roll up from the bottom to the top, ensuring the filling is secure inside.

Cook the Burritos

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

Serve

Remove the burritos from the skillet and let them cool for a minute. Cut in half if desired and serve with sour cream on the side.