Place the Ancho chillis and Guajillo chillis into a dry skillet and set it over medium-high heat.
Toast the chillis for 3-5 minutes, turning them frequently to prevent them from burning.
Remove the chillis from the skillet and place them on a cutting board. Remove the seeds and veins from each chili.
Place the Ancho chillis into one bowl, and the Guajillo in another bowl. Add enough hot water to cover the chillis and add a tablespoon of salt to each.
Soak the chillis for 20 minutes and then remove them from the liquid. Keep the soaking liquid.
Place the rosemary, thyme, cumin, coriander, Mexican oregano, bay leaf, cloves, and allspice in a spice grinder and blend until it is smooth.
Working in batches, add the drained chilis, 1 teaspoon of the ground spice mix, 2 garlic cloves, half of the onions, half of the red bell peppers, 1 1/2 teaspoon of salt, vinegar, and 1/2 cup of the chili soaking liquid to the blender and blend until smooth. Place the chili mixture into a large bowl and set it aside.
Repeat until all the chillis have been blended.
Add the chicken legs and thighs to the chili mixture and cover it with plastic wrap. Leave in the refrigerator overnight or at least for an hour.
Place 2 cups of water into a pot and set it over medium-high heat. Add a steamer basket on top of the pot once the water has come to a boil.
Cut three banana leaves into squares that are about 16 by 16 inches.
Place 1 chicken drumstick, 1 chicken thigh, and 1 Maguey leaf in the center of each banana leaf sqaure.
Bring the 4 edges of each square together and tie it with kitchen twine. Place the Mixiote de Pollo into the steamer basket, cover, and decrease the heat to medium-low. Cook for an hour.
Place the Mixiote de Pollo onto a serving dish, cut the kitchen twine, and open the parchment paper to reveal the chicken inside.
Serve on banana leaves with rice and any garnish you have on hand.