Tex-Mex Joes:
Prepare as above, except add 1/2 cup fresh or frozen whole kernel corn and 1 tablespoon chopped chipotle chile in adobo sauce with the tomato sauce. Serve on toasted rolls with slices of cheddar or pepper Jack cheese. (This mixture also makes a great taco filling.)
Veggie Joes:
Prepare as above, except omit ground beef. Cook onion and sweet pepper in 1 tablespoon hot olive oil over medium heat until tender. Add 2 cups cooked brown rice; one 15- to 16-ounce can red kidney beans (rinsed and drained) and 1/2 cup shredded carrot with tomato sauce.