Step 1

Blend the salsa. Prepare the following, placing them in a blender or food processor fitted with the blade attachment: Coarsely chop 4 roma tomatoes or 2 large tomatoes, 1/2 medium white onion, and 1 serrano pepper (remove the seeds and membranes first for a less spicy salsa). Add 1 garlic clove, 1/4 cup water, 2 teaspoons kosher salt, and 1 teaspoon black pepper. Pulse until chunky and coarsely chopped, adding more water if needed to thin. Taste and season with more kosher salt as needed.

Step 2

Cook the salsa. Heat 3 tablespoons vegetable oil in a small saucepan over medium-high heat until shimmering. Add the salsa and fry, stirring occasionally, for 3 minutes. Reduce the heat and simmer, stirring occasionally, until the sauce darkens, about 5 minutes. Reduce the heat to low and keep warm until ready to assemble.

Step 3

Fry the tortillas. Heat 1/4 cup vegetable oil in a large nonstick skillet over medium-high heat until shimmering. Lightly fry 4 corn tortillas: add 2 tortillas and fry until lightly brown and crisp but still pliable, 1 to 2 minutes per side. Transfer to a paper-towel lined plate and repeat with the remaining 2 tortillas. Remove any bits of fried tortillas from the pan with a slotted spoon.

Step 4

Fry the eggs. Reduce the heat to medium. Carefully crack 4 large eggs into the pan and season with kosher salt. Fry until desired doneness, 2 to 4 minutes for runny yolks. Meanwhile, warm the beans.

Step 5

Warm the refried beans. Place 1 cup refried beans in a microwave-safe bowl. Microwave in 20-second intervals on high power, stirring after each, until warmed through, about 60 seconds total. (Alternatively, warm on the stovetop over low heat.)

Step 6

Assemble the huevos rancheros. Spread the warm refried beans onto the tostadas. Place 2 tostadas on each plate, then top each tostada with a fried egg. Spoon the warm salsa over the eggs and garnish with cilantro if desired.