In a large mixing bowl, combine the grilled and diced chicken, cooked brown rice, black beans, corn, cheddar cheese, and chipotle ranch dressing. Season with salt and pepper to taste. Mix well until all ingredients are evenly coated.
Lay out the flour tortillas on a clean surface. In the center of each tortilla, place a generous amount of the chicken and rice mixture, leaving about 2 inches from the edges.
Add a few slices of avocado and a sprinkle of fresh cilantro on top of the mixture.
Fold the sides of the tortilla over the filling and then roll it tightly from the bottom. Ensure the filling is sealed inside.
Preheat a skillet over medium heat and place the burritos seam-side down on the skillet. Grill for about 3-4 minutes on each side or until the tortillas are golden brown and crispy.
Remove the burritos from the skillet and let them cool for a minute before slicing in half if desired.
Serve with lime wedges on the side for an extra zing!