In a medium bowl, combine the beef, 1 cup of cheese, 1/4 cup salsa, tortilla chips, green onions, chili powder and garlic salt. Shape into 3-4 patties. Cook on the preheated grill for about 5 minutes on each side, or until cook through as desired. Place on buns and top with additional cheese and salsa. Serve with lettuce and tomato slices.