Tacos Al Pastor

In a small skillet over medium heat, heat oil. Add annatto seeds, coriander, cumin, oregano, peppercorns, mustard seeds, and allspice berries and toast until fragrant, 1 minute. In a food processor or blender, add toasted seeds, garlic, orange juice, vinegar, and salt. Blend until it turns into a mostly smooth paste, scraping down sides as needed.

In a small skillet over medium heat, heat oil. Add chilis and toast until slightly charred and fragrant, 1 minute. In a food processor or blender, add toasted chilis, pineapple juice, achiote paste, vinegar, garlic, brown sugar, salt, cinnamon, and pepper. Blend until fully combined. 

Place pork in a large bowl and pour marinade over. Cover and refrigerate for 4 hours and up to overnight. 

Preheat grill to medium-high and brush with oil. Grill pork until slightly charred and cooked through, 6 minutes per side. Let rest on a cutting board for 5 minutes then cut into 1" pieces. 

Add pineapple and onions to grill and cook until slightly charred and onion is softened, 3 minutes per side. Break pineapple rings into large pieces.

Add tortillas to grill and cook until warmed, 1 minute per side.

On warmed tortillas, add pork, pineapple, onions, and cilantro. Serve with lime wedges.