Begin by heating about 1/4 inch of vegetable oil in a large skillet over medium heat until shimmering, about 5 minutes.

Carefully fry corn tortillas for 3-4 minutes on each side until golden brown and crispy.

In a small saucepan over low heat, gently warm refried black beans for about 5 minutes.

Spread a layer of warm refried beans on each crispy tostada.

In the same skillet, reduce heat to medium and cook eggs sunny-side up for about 2-3 minutes.

Place one cooked egg on top of each tostada, drizzle with red chile sauce, and sprinkle pickled onions if using.

Serve immediately, offering additional red chile sauce on the side.