Bring rice and 1 3/4 cups water to a boil in a covered saucepan. Reduce to low and cook for 15 minutes, then rest covered for 10 minutes and fluff.
Brown beef and onion in a skillet over medium-high heat for 8 minutes, breaking the meat into small crumbles and cooking it to 160°F. Drain excess fat.
Stir beans, roasted peppers, tomato sauce, chili powder, cumin, salt and black pepper into the beef. Simmer for 5 minutes until the mixture is thick with no puddle of liquid.
Spread rice and beef filling in separate shallow containers and refrigerate within 2 hours of cooking. Chill fully before assembling.
Warm tortillas briefly in a dry skillet just until flexible. Divide cold rice, beef filling and cheddar among them, fold in the sides and roll tightly.
Freeze after assembly: wrap each burrito tightly in parchment and then foil, place in a freezer bag, label and freeze for up to 2 months.
Reheat from frozen: remove foil, wrap one burrito in a damp paper towel and microwave on 50% power for 3 minutes, turn, then microwave on high for 2 to 3 minutes until its center reaches 165°F. Rest for 1 minute.
Crisp the hot burrito in a dry skillet over medium heat for 1 to 2 minutes per side if desired, and serve one per portion.