In a large bowl, mash pinto beans. Mix in 3/4 cup picante sauce and garlic. In a separate bowl, mix together 1/4 cup picante sauce, cilantro, black beans, and tomato. Place 1 tortilla in a pie plate or tart dish. Spread 3/4 cup pinto bean mixture over tortilla to within 1/2 inch of edge. Top with 1/4 cup cheese, and cover with another tortilla. Spread 2/3 cup black bean mixture over, and top with 1/4 cup cheese. Repeat layers twice more. Cover with remaining tortilla, and spread with remaining pinto bean mixture and cheese. Cover with foil. Bake at 400ºF (205 º C) for about 40 minutes. Cut into wedges, and serve with additional picante sauce and sour cream.