To make sauce: place tomates, serranos, onion, and garlic in a food processor or blender and puree until smooth. Heat 1 tbsp of the oil over medium-high heat. When very hot, add the sauce (which will sizzle) and cook, stirring, until the sauce is bright orange-red and thickened. Add salt to taste.** The sauce can be made a day ahead.
To assemble: make the refried beans (recipe below), or reheat if made ahead. Put some beans on a plate and make a hollow for the eggs. Fry or scramble your eggs any way you like them. Add eggs and top with sauce and cheese. Serve chips on the side of the plate.
Refried Black Beans