In a cast iron skillet, over medium heat, toast the ancho and chipotle chili for about 30-60 seconds, until fragrant. Do not burn. Set aside.
Wash and pat dry chicken thighs. Salt and pepper chicken thighs.
In a large enameled cast iron pot (6 quart will do fine), heat up about an 1/8 a cup or vegetable oil over medium heat.
In batches if necessary brown chicken thighs, about 3 minutes each side. Remove and set aside.
Add the chopped onions and habanero half, cook while occasionally stirring till onions start to become translucent, then add garlic till onions start to brown.
Add Chilies, beer, tequila, canned tomatoes, chicken broth, cumin, oregano and salt and pepper to taste. Turn down to medium low and cook until chilis become soft (15 minutes or more, do not stop till they are soft). When soft, remove from heat to cool.
Pre-heat oven to 325° F
Add Chili-beer mixture to a blender in batch and blend till smooth.
Add chicken back to pot and cover in chili-beer-blender mixture.
Cover and place in oven for 2 hours.
After two hours, remove lid and cook for additional 30 minutes (stirring when needed for sauce to not stick or burn on side).
Remove from oven, shred chicken.
Warm tortillas in a cast iron on the stove (very important, do not skip)
In tortilla, place chicken, then onion, cilantro and squeeze lime.