Pickled Beef Tostadas with Tomatillo Salsa

• 4 large tomatillos, husked, coarsely chopped
• 1 serrano chile, seeds removed if desired, chopped
• 1 avocado, finely chopped

Kosher salt

• 1 1-lb. piece beef brisket, trimmed, sliced against the grain ½” thick

Kosher salt and freshly ground black pepper

• ½ habanero chile, seeds removed if desired, finely chopped
• ½ serrano chile, seeds removed if desired, finely chopped
• ½ teaspoon finely grated lemon zest
• ¼ cup fresh lemon juice
• ½ teaspoon finely grated lime zest
• ¼ cup fresh lime juice
• 1 tablespoon fish sauce (such as nam pla or nuoc nam)
• ¼ head green cabbage, thinly sliced (about 3 cups)
• ½ red onion, thinly sliced
• 4 tostada shells
• 1 avocado, cut into 1” pieces
• 3 tablespoons finely chopped fresh cilantro

1. Pulse tomatillos and chile in a food processor to a coarse purée. Transfer to medium bowl and fold in avocado; season with salt.
2. Season brisket with salt and pepper; loosely cover and chill at least 2 hours.
3. Combine habanero chile, serrano chile, lemon zest, lemon juice, lime zest, lime juice, and fish sauce in a medium bowl; set chile mixture aside.
4. Prepare a grill for high heat. Grill brisket until lightly charred on both sides, but still rare, about 1 minute per side. (Alternatively, cook on a grill pan over high heat.) Let rest 15 minutes.
5. Cut brisket into ¼” pieces, add to reserved chile mixture, and toss to combine; let sit 20 minutes. Add cabbage and onion and toss to combine.
6. Top tostadas with beef mixture, avocado, salsa, and cilantro.
7. Do Ahead: Brisket can be seasoned 12 hours ahead. Keep chilled.