Heat a large skillet over medium-high heat. Cook and stir beef in the hot skillet until browned and crumbly, 5 to 7 minutes. Add onion and garlic. Drain and discard grease. Add refried beans and burrito seasoning packet. Add green chiles and heat over low heat, stirring occasionally, until heated through, about 5 minutes more.

Wrap tortillas in a damp paper towel and cook in a microwave oven until warmed through, about 10 seconds.

Spoon about 2 tablespoons beef mixture into a warm tortilla. Add a tablespoon or more of Cheddar cheese. Fold both sides in, then fold and roll over mixture to seal burrito. Repeat with remaining tortillas, filling, and cheese.

Wrap burritos in waxed paper or place in plastic bags and store in the freezer for use in lunch boxes.