In a skillet over medium heat, cook the ground beef until browned, breaking it apart with a spatula. Drain any excess fat.
Add taco seasoning and water to the skillet, stirring to combine. Simmer for about 5 minutes until thickened. Taste and season with salt and pepper if needed.
In a large bowl, combine the cooked rice, cooked beef mixture, shredded cheddar cheese, and nacho cheese sauce. Stir until well mixed.
Warm the flour tortillas in a dry skillet or microwave until pliable.
Lay each tortilla flat and spread a generous scoop of the beef and rice mixture down the center.
Add a dollop of sour cream, diced tomatoes, and sprinkle with green onions and cilantro if using.
Fold the sides of the tortilla inwards, then roll it up from the bottom to form a burrito.
For an extra melty experience, heat a skillet over medium heat and place the burritos seam-side down for 2-3 minutes until golden and crispy. Flip and repeat.
Notes
Serve with additional nacho cheese for dipping and a sprinkle of cilantro for freshness.