First, make foil "handles." Fold a 30-inch long piece of foil in half lengthwise. Place in bottom of a slow cooker with both ends hanging over top edge of cooker.The foil strip will make it much easier to remove the burrito stack when done.
Lightly grease crockpot. In saucepan, combine the first six ingredients; simmer for 20 minutes over low heat. In a large skillet over medium heat, brown ground beef with onion, bell pepper, and minced jalapeno or mild peppers. Drain off fat. Stir about 1/3 of sauce mix into the browned beef mixture.
Spoon a small amount of sauce into bottom of the slow cooker.
Spread a small amount of refried beans over one of the flour tortillas. Place the tortilla on top of sauce in Crock Pot, tearing to fit if necessary. Spoon meat mixture over tortilla and then top with a small amount of the shredded cheese. Continue layering until tortillas are used or within an inch of top of crockpot. Cover and cook on LOW 6 to 8 hours or on HIGH for 3-4 hours. Lift burritos out by the foil handles and place on serving plate. Cut in wedges; garnish with chopped tomato, shredded lettuce, sour cream, sliced ripe olives, or your own favorite combination. Serves 4 to 6.