This achiote marinade transforms humble chicken tacos into something bright, bold, and beautiful. A quick salsa combines citrus and spice, balanced with creamy avocado.
Preheat the oven to 400°F. Remove the chicken from the marinade and season with salt. In a large cast-iron skillet or ovenproof pan over medium heat, warm 3 tablespoons olive oil. Add the chicken and cook until golden on the first side, 5 minutes. Flip the chicken and transfer the pan to the oven. Bake until the chicken is no longer pink at the center, 10 minutes. Transfer the chicken to a cutting board to rest, 5 minutes. Slice the meat across the grain.
Meanwhile, thinly slice about ½ cup of shallot. Seed and thinly slice the chile, if using. In a bowl, combine the shallot and chile, drizzle with the juice of ½ lime and ½ orange, season with salt, and toss to coat.
In a bowl, combine the cabbage slaw, juice of ½ lime, 1 tablespoon olive oil, and a pinch of salt, and toss to coat. Peel, pit, and dice the avocado. Pick the cilantro leaves and toss the stems.
To warm the tortillas, in a dry pan over medium-high heat, flash the tortillas for 30 seconds on each side. Wrap them in a clean towel to steam through and keep warm.
To build the tacos, place the tortillas on plates, doubling up, if you like. Fill with the chicken and shallot-chile mixture, top with the avocado, and scatter with the cilantro leaves. Serve warm, with the cabbage slaw on the side.