Place the guajillo chiles in a small pot and cover with water. Boil over medium heat for about 10 minutes or until soft. Remove from the water and let cool. Blend with all the marinade ingredients: guajillo chiles, garlic, achiote paste, orange juice, white vinegar, onion, oregano, cumin, and salt, until you get a smooth sauce.

Slice the mushrooms thinly and place them in a bowl. Pour the sauce over them through a strainer, and mix well until the mushrooms are fully coated. Cover with plastic wrap and refrigerate for 1 hour.

Cut the pineapple into small cubes and sauté with 1 teaspoon of olive oil. Set aside.

Finely chop the onion and cilantro.

After marinating, sauté the mushrooms over medium heat with a splash of oil. Cook until they are soft but not dry.

Warm the tortillas. Serve your tacos and top with pineapple, cilantro, and onion. You can also add a squeeze of lime and some spicy salsa. Enjoy!