In a deep skillet, cook 1 pound of ground beef, stirring constantly, until it is brown and crumbly. Skim off any excess fat. Add 1 cup chopped onion and ? cup chopped green pepper, and continue to cook the beef and vegetables, until the vegetables are soft and clear. Add a 10 oz. jar of taco sauce, 1 tablespoon of taco seasoning, ? tablespoon chili powder, and 1 teaspoon salt. Cook for 10 minutes, until bubbly and flavors are blended. Remove from heat, and begin the assembly of your tacos. Fill each of the 8 taco shells with about 1/3 cup of the cooked beef mixture. Place these in a baking pan or glass dish that has sides, to keep them upright, and bake at 350-degrees for 10 minutes, or until crisp and beginning to brown. While the tacos are baking, heat a 15 oz. can of refried beans to steaming hot. When the tacos have finished baking, remove them from the oven, and prepare them for serving, one by one. For each taco, take a flour tortilla, spread one side of it with 2 tablespoons of hot refried beans. Immediately, tuck a fresh-baked taco on top of the flour taco, against the refried beans. Squeeze together to mold the soft taco (with its refried beans) on the outside of the crisp taco (with its beef mixture). Place each finished taco on a serving tray. Serve individually with toppings of shredded sharp Cheddar cheese, shredded lettuce, and chopped tomatoes, to taste. Add some sour cream and jalapeno slices on the side, if desired. This is a popular and fun dinner, particularly with the kids!