Heat oven to 450°F.
Sauté beef in skillet until no longer pink, 8 to 10 minutes.
Add tomato, chili powder, salt, pepper, cayenne and cumin; cook, stirring, 1 minute. Stir in soup; simmer 5 minutes.
Place 1 bread shell on baking sheet. Evenly spread half the meat sauce over crust, leaving 1-inch border all around. Sprinkle half the cheese and half the green pepper over top. Repeat with the other crust and remaining ingredients.
Bake in lower third of 450°F oven for 8 to 10 minutes or until heated through and cheese is melted. Let stand 5 minutes before slicing.