1-1/4 pounds ground beef
1 medium onion, chopped
4 garlic cloves, minced
2 cups salsa
1 can (16 ounces) refried beans
1 can (15 ounces) black beans, rinsed and drained
1 can (10 ounces) enchilada sauce
1 can (4 ounces) chopped green chilies
1 envelope taco seasoning
1/4 teaspoon pepper
6 flour tortillas (10 inches)
3 cups shredded Mexican cheese blend, divided
2 cups crushed tortilla chips
Sliced ripe olives, guacamole, chopped tomatoes and sour cream, optional