Taco Lasagna

2 pounds ground beef
2 envelopes taco seasoning
3 cloves pressed garlic
1/2 teaspoon cayenne pepper
1 1/2 cups water
1 tablespoon cornmeal
24 corn tortillas
1 (24 ounce) jar salsa
1 cup chopped scallions
1 pint sour cream
1 tablespoon chili powder
3 cups shredded Monterey jack cheese
3 cups shredded Cheddar cheese

Preheat oven to 375