In a skillet over medium heat, cook the ground beef until browned and cooked through. Drain excess fat if necessary. Stir in the taco seasoning with a splash of water and simmer 1–2 minutes to coat the meat evenly.

In a bowl, mix the cooked white rice with the nacho cheese sauce and chipotle sauce (adjust to taste). Fold in the sour cream for creaminess.

Lay a flour tortilla flat. Spoon a quarter of the cheesy rice mixture down the center, top with a portion of seasoned ground beef, then sprinkle equal parts shredded cheddar and mozzarella. Fold the ends and roll tightly into a burrito.

Heat a large skillet or griddle over medium heat. Spread a thin layer of butter or oil on the outside of each burrito. Place seam-side down in the skillet and cook for 2–3 minutes per side, pressing gently, until the tortilla is golden brown and the cheeses are melted. Rotate to get an even crust on all sides.

Remove burritos to a cutting board and let sit 1–2 minutes to let fillings settle. Slice in half on the diagonal for a melty cross-section.