Place chuck roast in a crockpot and add burrito mix and water. Turn the roast a few times and swish it around to blend in the mix.
Add the salsa; cover and cook on low heat for 12 to 14 hours or until the meat is falling apart.
Wrap flour tortillas in foil and warm in a 325° F oven for 10 to 15 minutes. While tortillas are warming, heat the beans.
Place some of the meat, beans, and grated cheese, on the middle of the tortillas, leaving about ½ inch at the top and the bottom and have the mixture go out to the sides about a couple of inches. Fold as for a burrito. Serve warm and drizzle with the hot sauce.