Preheat oven to 425 degrees. Scrub potatoes and cut into 1⁄2-inch thick wedges. Place potatoes into a medium-sized bowl with the oil, garlic salt, and Mexican seasoning. Stir well to coat potatoes with oil and seasonings. Transfer to a large baking sheet and spread into a single layer. Bake for 25–30 minutes, stirring several times, until crisp and golden brown. Top with cheese, beans, tomatoes, olives, onions, and chiles. Bake for 5 minutes longer to melt cheese. Optional: serve with salsa, guacamole, and sour cream.