Heat a large skillet or comal over medium-high heat. Spread butter over the cut side of the bolillo roll and place buttered side on hot skillet.
Toast the bolillo for a couple of minutes or until it’s nice and brown. Remove from skillet and place rolls on a baking sheet.
Spread a layer of refried beans, then a layer of shredded cheese.
Bake the bolillo rolls for about 15 minutes or until cheese is melted and it turns golden brown.
Remove from oven and top with salsa fresca. Serve warm.