Zarandeado Recipe

Prepare marinade

In a blender or small food processor combine serrano chiles (seeded for less heat if desired), garlic, soy sauce, lime juice, olive oil, brown sugar, smoked paprika, kosher salt and black pepper. Blend until smooth and emulsified, scraping down sides once. Taste and adjust for heat or salt.

Marinate the tuna

Place the bluefin tuna loin in a shallow dish or resealable bag. Pour half of the marinade over the tuna, reserving the other half for basting. Turn the tuna to coat evenly. Marinate in the refrigerator for 20–30 minutes (no more than 45 minutes to keep texture). Remove tuna from refrigerator 10 minutes before cooking to come closer to room temperature.

Sear or grill (zarandeado-style)

Preheat a cast-iron skillet or grill over high heat until very hot and lightly smoking. Brush the tuna with a little neutral oil. Sear the loin 45–60 seconds per side for rare (adjust time for desired doneness). While searing, baste with reserved marinade once or twice using a spoon or brush to build a caramelized, slightly charred exterior. For thicker loins, sear the edges 30 seconds each. Remove tuna and let rest on a cutting board 5 minutes before slicing.

While tuna marinates, whisk together sour cream, mayonnaise, finely chopped chipotle in adobo, adobo sauce, lime juice, honey and kosher salt until smooth. Taste and adjust heat or acidity — add a little more adobo sauce for heat or a splash of lime if too rich. Chill in refrigerator until ready to serve.

Combine apple cider vinegar, water, sugar and salt in a small saucepan and heat just until sugar and salt dissolve. Place thinly sliced red onion in a heatproof jar or bowl and pour the warm pickling liquid over the onions. Let cool to room temperature, then refrigerate at least 20 minutes (up to 24 hours) — quick-pickling will soften and brighten the onions for topping.

Slice the rested tuna into 1/4-inch thick slices or bite-sized cubes, depending on how you want to serve on the tostada.

Warm blue corn tostadas briefly in a 350°F (175°C) oven for 3–5 minutes or in a dry skillet 30–60 seconds per side until crisp and slightly toasted.

Spread about 1 tablespoon of chipotle crema onto each tostada. Arrange 3–4 slices or a small mound (about 2–3 oz) of seared tuna on top. Add a few pickled onion slices, a sprinkle of micro cilantro, and a light drizzle of finishing oil (mix neutral oil with chile oil if using). Finish with a squeeze of lime and a pinch of toasted sesame seeds, if desired.

Serve immediately while tuna is still slightly warm and tostadas are crisp.

Combine neutral oil and chile oil in a small bowl and stir. Use sparingly to drizzle over plated tostadas for sheen and a touch of extra heat.