Heat a skillet over medium heat. Add ground beef and cook until browned, breaking it apart as it cooks. Drain excess grease.
Stir in taco seasoning and water. Simmer for 3–4 minutes until thickened. Remove from heat.
Season cooked rice lightly and fluff with a fork.
Warm tortillas until soft and pliable.
Lay a tortilla flat. Add rice, seasoned beef, shredded cheese, nacho cheese sauce, and sour cream.
Fold in the sides and roll tightly into a burrito.
Optional: Toast burritos seam-side down in a skillet until lightly golden.
Serve warm.