Generously Salt and Pepper the 2 pounds boneless skinless chicken thighs on both sides. Add about 2 tablespoons vegetable oil to a large heavy bottomed pot and heat until the oil is very hot. Brown the chicken in batches, leaving room between the pieces of chicken so they turn a golden brown on one side before flipping. Transfer the browned chicken to a plate and repeat.
2 pounds boneless skinless chicken thighs, Salt, Pepper, 2 tablespoons vegetable oil
Turn down the heat to medium low, add the 3 small onions and 4 cloves garlic to the pot, and cover with a lid for 10 minutes. When you remove the lid, the onions should be wilted and cooking in their own juices. Use a wooden paddle to scrape up all the browned bits (a.k.a. chicken flavor) from the pan, then turn up the heat to medium high to burn off the liquid. When most of the liquid has evaporated, turn the heat back down and stir and continue to caramelize the onions until they are brown and glossy (another 20-30 minutes).
3 small onions, 4 cloves garlic
Meanwhile, tear up the 3 dried ancho chilies and 3 dried guajillo chiles into small flat pieces and place them in a single layer on a sheet pan. Roast in a 350 degree oven until they are fragrant, but be careful not to burn them as they will become bitter. Transfer the roasted peppers to a bowl and cover them with very hot water. Once the peppers are soft, transfer them to a food processor or blender adding in about ½ cup of the water they were soaking in along with the 14 ounces whole stewed tomatoes. Puree the peppers and tomatoes until they form a smooth sauce.
3 dried ancho chilies, 3 dried guajillo chiles, 14 ounces whole stewed tomatoes
When the onions are done caramelizing add the pepper puree, along with the chicken, 2 cinnamon sticks, 1 bay leaf and 1 tablespoons lemon juice. Bring to a boil over medium high heat, then reduce the heat to the lowest setting, partially cover with a lid and cook until the chicken falls apart when prodded with a fork (about 1 ½ hours).
2 cinnamon sticks, 1 bay leaf, 1 tablespoons lemon juice
When the chicken is done, remove the bay leaf an cinnamon sticks, then use 2 forks to shred the meat. Taste the sauce and add salt to taste. Serve with sliced avocados, fresh cilantro, lime wedges and corn tortillas.
salt, corn tortillas