Cut each onion in half, leaving the root end intact so it holds together during boiling.

Core the tomatoes. Remove the stems from the jalapeños and serranos, and optionally deseed them for a milder heat.

Prepared onions

Tomatoes

Jalapeños

Serranos

4 of the garlic cloves

Bring to a boil and cook for about 10 minutes, or until the tomatoes are softened. Add water if needed to keep everything submerged.

Using a slotted spoon, remove the vegetables and allow them to cool slightly.

Peel the skins off the tomatoes. (Tip: soak them in cold water briefly if the skins stick.)

Trim the roots off the onions. Remove the seeds from the chilies if desired.

All cooked vegetables

Remaining 2 garlic cloves

Chopped guajillo chilies

Salt and pepper to taste

Blend until the sauce is smooth.

Pour the blended sauce into a saucepan. Bring to a boil, then reduce heat and let simmer for 10 minutes, stirring occasionally. The sauce should slightly thicken and deepen in flavor.

Heat about 1 tablespoon of bacon grease or oil in a cast-iron skillet over medium-high heat.

Place a tortilla in the pan, flip to coat both sides, and fry until soft and slightly puffed—about 30 seconds per side. They should stay flexible, not crispy.

Repeat with remaining tortillas. Keep warm on a plate covered with foil.

Add more grease if needed to the same skillet. Crack in the eggs and fry them to your preference—sunny-side up or over-easy is traditional.

Place one or two tortillas on each plate. Top each with a fried egg.

Spoon the warm sauce over the top, then sprinkle with shredded cheese.