Preheat oven to 350 degrees.
Make the Quick Pickled Onions and the Smashed Avocado (see recipe below).
Warm the refried bean in a small pan over medium heat.
Place bacon strips on a sheet pan and cook at 350 degrees for 20 minutes.
Remove from oven and place on either wire rack or paper towels to catch the grease.
Butter each half of the Bolillo rolls.
Turn oven to broil and broil the Bolillo rolls until just browned. Remove from oven.
Heat a large sauté pan over medium high heat.
Add 1 tbsp. butter to the pan and let it melt.
Crack each egg separately in the pan and fry. Using a spatula, gently pull any egg white towards the egg yolk to create a nice round shape.
After about a minute, add 1 tbsp. water to the pan and cover. Cook until egg white is opaque and egg yolk is slightly soft to the touch. Remove from heat.