2 large plum tomatoes
1 medium onion
6 guajillo chiles, stems and seeds removed
15 dried pequin chiles, stems removed
6 garlic cloves, peeled
4 dried or fresh epazote leaves
2 tsp. dried oregano
1 Tbsp. Diamond Crystal or 1¾ tsp. Morton kosher salt, plus more
2 lb. skinless, boneless chicken thighs
Vegetable oil (for grilling)
Cilantro leaves with tender stems and lime wedges (for serving)

Preparation
Step 1
Combine 2 large plum tomatoes, 1 medium onion, and 6 guajillo chiles, stems and seeds removed, in a small saucepan; pour in just enough water to cover. Set over high heat and bring to a boil. Reduce heat so mixture is at a simmer and cook 15 minutes. Drain and transfer to a blender. Add 15 dried pequin chiles, stems removed, 6 garlic cloves, peeled, 4 dried or fresh epazote leaves, 2 tsp. dried oregano, and 1 Tbsp. Diamond Crystal or 1¾ tsp. Morton kosher salt; cover and purée until smooth. Let salsa cool 10 minutes.

Step 2
Season 2 lb. skinless, boneless chicken thighs all over with salt; place in a medium bowl. Pour half of salsa over; turn to coat. Cover and chill at least 45 minutes and up to 12 hours. Place remaining salsa in a small bowl; cover and chill until ready to use.

Step 3
Prepare a grill for medium-high heat; oil grate with vegetable oil. Remove chicken from salsa, letting excess drip back into bowl; transfer to a plate. Discard salsa used for marinating. Grill chicken, basting occasionally with remaining salsa and turning halfway through, until cooked through and lightly charred, 10–12 minutes. Transfer chicken to a platter. Brush with remaining salsa and top with cilantro leaves with tender stems. Serve with lime wedges.

By Rachel Gurjar