A mollete, native to northern Mexico, is made with bolillos sliced lengthwise and partially hollowed, filled with frijoles refritos, and topped with cheese and slices of jalapeño or serrano peppers. It is then grilled in an oven until the cheese melts.
Julienne the onions, potato skins and jalapeños.
Add a couple of tablespoons of olive oil on a heavy skillet over medium high heat. Add all the vegetables. Stir sparingly to allow for caramelization and browning. Add salt to taste.
Keep cooking until all the ingredients have caramelized and they are golden brown.
Slice each bun in half. Spread some refried beans on top of the bread. Top with the jalapeños and shredded cheese. Broil for a few minutes until the bread is crispy and the cheese has melted and browned.