Preheat the oven to 350 degrees F (175 degrees C). Brown the ground beef in a skillet over medium-high heat. Drain excess grease, and add the onion, bell pepper, and corn. Cook for about 5 more minutes, or until vegetables are tender.
Stir in the taco sauce, and season with chili powder, garlic salt and cumin, stirring until blended. Cook until heated through, then remove from heat, and set aside.
Open the can of beans, and spread a thin layer of beans onto each of the tortillas. Spoon the beef mixture down the center, and then top with as much shredded cheese as you like.
Roll up the tortillas, and place them seam-side down onto a baking sheet. Brush the tortillas with melted butter.
Bake for 30 to 35 minutes in the preheated oven, or until golden brown. Serve with lettuce and tomato.