In a 12-inch skillet over medium heat, brown ground beef for 8 to 10 minutes, breaking it up until no longer pink. Drain excess grease, add taco seasoning and ¼ cup water. Simmer for 5 minutes until sauce thickens.

Combine cooked rice with sour cream in a bowl, mixing until well combined. Warm flour tortillas in a dry skillet over low heat for 20 seconds per side, or microwave for 20 seconds wrapped in damp paper towel. Keep covered with clean towel.

On each warmed tortilla, spread ½ cup rice mixture in center, leaving 2 inches clear on all sides. Layer with a quarter of seasoned beef, 2 tablespoons nacho cheese sauce, ½ teaspoon chipotle sauce, and generous handful each of cheddar and mozzarella cheese.

Fold burrito by bringing bottom edge up and over filling, fold in both sides tightly toward center, then roll forward to seal with seam on bottom. Keep tension on tortilla for compact wrap.

Heat large 12-inch skillet over medium heat and add ½ tablespoon butter. Once melted and sizzling, place burrito seam-side down and grill for 3 to 4 minutes until deep golden brown. Add another ½ tablespoon butter, flip carefully, and grill for another 3 to 4 minutes. Gently press down with spatula.

Remove from skillet and let rest for 1 minute before slicing in half diagonally.