Salvadorean papas fritas

A few years ago I went to El Salvador with my mom for the Fiestas Patrias, during which we bought papas fritas (french fries) from one of the booths. I know this may seem like a silly question but I can't remember what they put on the french fries. I know it has ketchup, cheese, salt (optional), and a white sauce (don't remember if it's mayonaise or something else). I don't even remember what kind of cheese was used either! Please, if someone could just fill in the blanks here it would be greatly appreciated.