Heat 1 cup vegetable oil in a large skillet or deep pan over medium-high heat until it reaches 350°F (or a small piece of tortilla sizzles immediately).

Fry tortillas one at a time: carefully slide a tortilla into the hot oil, hold it flat with tongs and fry 45–60 seconds per side until crisp and golden. Drain on a paper towel–lined rack. Immediately sprinkle both sides lightly with fine salt. Keep warm in a single layer in a low oven (200°F / 95°C) if preparing ahead.

Salad & Beans

In a medium bowl combine shredded lettuce, drained black beans, diced red onion and chopped cilantro.

Toss with 1 tablespoon fresh lime juice, 1/4 teaspoon salt and 1/8 teaspoon black pepper. Taste and adjust seasoning. Refrigerate until assembly (but drain any excess liquid before using).

Salsa Roja

Preheat a dry skillet or comal over medium-high. Halve the jalapeño lengthwise (remove seeds if less heat desired) and roast, along with tomatoes, onion quarters and garlic cloves, until skins char and tomatoes soften — about 6–8 minutes, turning as needed.

Transfer the roasted vegetables to a blender or food processor. Add 1 teaspoon vegetable oil, 1/2 teaspoon salt and 1/2 tablespoon lime juice. Pulse to a chunky salsa texture (or smooth if preferred). Taste and adjust salt or lime.

Guacamole

Halve and pit the avocados, scoop flesh into a bowl and mash lightly with a fork, leaving some small chunks for texture.

Stir in 1 tablespoon lime juice, 1/2 tsp salt, 1/2 minced jalapeño (optional), 1 tablespoon chopped cilantro and 1 tablespoon minced red onion. Adjust seasoning to taste and cover with plastic wrap (touching surface) to prevent browning until ready to assemble.

Assembly & Garnish

Place a crispy tortilla tostada on a plate. Spread about 2 tablespoons of guacamole evenly over the tostada as a sticky base to hold toppings.

Add about 1 cup of the lettuce-and-bean mixture on top of the guacamole, pressing gently so it adheres.

Spoon 2–3 tablespoons of salsa roja over the salad layer per tostada.

Drizzle about 1 tablespoon sour cream over each assembled tostada (or dollop).

Sprinkle 2 tablespoons crumbled queso fresco over each tostada and garnish with a few thin jalapeño slices and a small cilantro sprig if desired.

Serve immediately with lime wedges on the side to squeeze over just before eating.