Tacos

1 dozen taco shells
1/2 onion, chopped
1 tablespoon vegetable oil
1 pound ground beef
2 cloves garlic, crushed
1/4 teaspoon cumin
1/4 teaspoon pepper
1/4 teaspoon salt
Lettuce, shredded
Cheddar or longhorn cheese, grated
Tomatoes, chopped
Ripe olives, chopped
Taco sauce

Saut