Summer Tostadas with Salsa Macha

To make the salsa macha, in a large saucepan over medium-high heat, warm the avocado oil until hot but not smoking, 2 to 3 minutes. The oil is ready when it starts sizzling immediately after a piece of chile is dropped in. Add the ancho, guajillo and arbol chiles and fry, stirring constantly, until fragrant, about 1 minute. Be careful not to overfry and burn the chiles. Using a slotted spoon, transfer the chiles to a high-powered blender.

Add the pistachios, pumpkin seeds and garlic to the pan and fry over medium-high heat, stirring constantly, until light to medium golden brown, about 1 minute. Remove the pan from the heat. Strain the pistachios, pumpkin seeds and garlic through a fine-mesh strainer set over a small bowl and transfer to the blender, reserving the oil.

Pour the oil back into the pan, add the sesame seeds and fry over medium-high heat, stirring constantly, until a few seeds turn light brown, about 1 minute. Remove from the heat and let the seeds and oil cool for 5 minutes. The seeds will begin to darken and turn medium golden brown.

Carefully pour the sesame seeds and the oil into the blender and add 1 1/2 tsp. kosher salt. Pulse the mixture 4 or 5 times until the pieces are fairly small and uniform in size. Do not overblend; the mixture should have lots of crunchy bits and not be pureed. Stir in the cider vinegar. Taste and adjust the seasoning with kosher salt. Use immediately, or transfer to an airtight container and refrigerate for up to 1 month.

To make the tomatillo salsa, in a high-powered blender or a food processor, combine the tomatillos, white onion, cilantro, garlic, jalapeño and 1 tsp. kosher salt and blend on medium speed for 30 seconds. Stop the blender and scrape down the sides of the blender; the salsa should be thick and on the chunkier side, not smooth. Use immediately, or transfer to an airtight container and refrigerate for up to 1 week.

To make the pickled onions, in a large bowl, stir together the red onions, bay leaves and oregano; set aside. In a small saucepan over medium-high heat, combine the red wine vinegar, orange juice, sugar and 1 tsp. kosher salt and bring to a simmer, stirring to dissolve the sugar and salt, then simmer for 1 minute. Pour the vinegar mixture over the onions, submerging the slices completely. Let cool for 15 minutes, then cover and refrigerate for at least 1 hour or up to 2 weeks.

To make the sour cream–crema spread, in a medium bowl, combine the sour cream, mayonnaise, crema and 2 tsp. kosher salt. Season to taste with pepper. Use immediately, or transfer to an airtight container and refrigerate for up to 1 week.

If cooking steak, season the steak with kosher salt and pepper. In a large nonstick fry pan over medium-high heat, warm the avocado oil until glistening, about 2 minutes. Add the steak and sear, turning once, until an instant-read thermometer inserted into the thickest part of the steak registers 135°F (57°C), 2 to 4 minutes per side, or until done to your liking. Reduce the heat if the pan starts to smoke. Transfer the steak to a cutting board and let rest for 10 minutes, then slice the meat against the grain.

If cooking prawns, season the prawns with kosher salt and pepper. In a large nonstick fry pan over medium-high heat, warm the avocado oil until glistening, about 2 minutes. Add the prawns and sear, turning once, until just cooked through.

To assemble the tostadas, spread about 2 Tbs. of the sour cream–crema onto each tostada. Dollop with the tomatillo salsa, add the steak or prawns and top with the tomatoes. Sprinkle with flaky sea salt, pepper and feta, then spoon on the salsa macha. Top with the pickled onions and garnish with the green onions and micro cilantro. Serve immediately. Serves 12.

Williams Sonoma Test Kitchen