Toast and soak the chiles. To make the marinade, heat a small pan or comal over medium heat. Once hot, add the dried chiles and toast, turning frequently, until the color has darkened and the chiles are fragrant. Meanwhile, bring a small pan of water to a boil over medium high heat. Once the chiles are toasted place them in the boiling water. Remove from heat, submerge the chiles in water and set aside to soften, about 15 minutes.

Cut the pineapple. We will be using half of the pineapple for the salsa and half for the marinade. Slice the top and bottom off the pineapple then remove the skin by running a sharp knife down the sides of the pineapple in between the skin and the flesh. Cut the pineapple in half vertically. Set one half aside for the salsa. Remove the core from the other half, cut into large pieces and place in a blender.

Blend marinade. Drain chiles and add to the blender with the pineapple. Add the chipotle chiles, 2 cloves garlic, lime juice from 1 lime, achiote paste, oregano, and salt. Blend on high until smooth.

Prep pork. Place pork steaks in a single layer in a dish large enough to hold them plus the marinade. Pour the marinade over the pork and turn to coat. Cover with plastic wrap and marinate in the refrigerator overnight.

Heat grill. Before lighting the grill, remove the pork from the refrigerator and let sit at room temperature while the grill heats and you make the salsa. Heat the grill so one side of the grill is at high heat and the other side is medium.

Grill pineapple for salsa. Place the reserved pineapple half on the grill and cook, turning occasionally until the outside is nicely charred on all sides, about 15 minutes. Remove to a cutting board, let cool.

Make salsa. Remove core from the grilled pineapple and cut into small dice. Mince the red onion, serrano, and fresh cilantro and place in a large bowl. Squeeze the other lime half over the salsa, season with salt and stir. Taste and add more lime juice and/or salt as needed.

Grill pork. Place pork steaks on the high-heat side of the grill, keep the dish with the marinade close by. Grill pork until one side is deeply marked with grill marks, about 7-15 minutes (depending on how hot your grill is).

Flip and brush with a layer of the leftover marinade then grill another 7-15 minutes on the other side. Flip again moving them to the cooler side of the grill and brush again with the marinade.

Continue cooking on that side another 10 minutes. Flip one last time—do not brush with marinade anymore—and cook on that other side another 10 minutes or until the meat is nicely crisp on the outside and firm. Internal temperature should read 150°F (you may have to do one more 10 minute flip depeding on the how hot your grill is).

Remove to a cutting board, cover with aluminum foil, and let sit 5-10 minutes.

Slice pork and serve. Thinly slice pork into small, bite-sized pieces. Serve in warm tortillas with grilled pineapple salsa on top and lime wedges for squeezing.