Flavor — crunchy, creamy, luscious — you'll see why.
- 1 medium white onion
- 1 pound tomatoes, quartered
- 2 large garlic cloves
- 1 or 2 fresh serrano chiles, stemmed
- 1/2 cup plus 2 tablespoon vegetable oil, divided
- 3 cups shredded iceberg lettuce
- 6 large radishes, halved and sliced
- 1/2 cup chopped cilantro, divided
- Fresh yellowfin tuna or ahi tuna 4 portions-
- 6 (6-inch) corn tortillas
- 1 (1-pound) can refried beans, heated
- 1 avocado, halved, pitted, and peeled
- 1/2 cup Mexican crema or sour cream
- 1/4 cup crumbled queso añjo (aged white cheese, also called cotija) or ricotta salata
- Squeeze of lime
Cut half of onion into 3/4-inch wedges, then chop remainder. Toss onion wedges, tomatoes, garlic, and whole chiles with 2 tablespoons oil in a 4-sided sheet pan, spreading in 1 layer.
Broil about 4 inches from heat until softened and charred, 10 to 15 minutes. Meanwhile, toss together lettuce, radishes, chopped onion, and half of cilantro.
Purée tomato mixture in a blender along with one or both roasted serranos (to taste) and 1 teaspoon salt until smooth(use caution when blending hot foods). Place tuna in a heated pan- sear 30 seconds on each side. Rub mixture with puree.
Heat remaining 1/2 cup oil in a heavy medium skillet over medium-high heat until it shimmers. Fry tortillas, 1 at a time, turning once or twice and pressing with tongs to immerse, until golden brown, 45 to 60 seconds per tortilla. Drain briefly on paper towels, then transfer to plates.
Spread tortillas thickly with heated refried beans, then top with tuna mixture. Slice avocado over tostadas and dollop with crema.
Mound lettuce mixture on top and sprinkle with cheese.
Serve with: Margaritas