To the bowl of a food processor or blender add 1/2 cup water, onion, garlic, 2 tablespoons adobo sauce (from can of chili’s), 1 chipotle chili, also from can, chile powder, 1 tablespoon oil, 1 teaspoon salt, cumin, vinegar, oregano, and black pepper.
Blend until completely smooth, add 1/2 cup water stirring to combine.
Place chicken in a large non-reactive container, with enough room for the adobo sauce.
Pour sauce over chicken, turning chicken to coat evenly. Cover and refrigerate for 10 to 12 hours (overnight) for the most intense flavor; chicken can be marinated for up to 2 days. Remove chicken from marinade, pat dry with paper towels, and place in a medium bowl. Season with remaining teaspoon salt.
Heat oven to 375°F In a large cast-iron skillet, over medium, heat remaining 2 tablespoons oil. Cook chicken until dark golden brown on one side, about 5 minutes; turn chicken over and continue to cook until the underside is dark brown, another 5 minutes. Remove skillet from heat and transfer to oven. Cook until chicken is opaque throughout, but still juicy, about 8 to 10 minutes chicken should be165°F on a instant-read thermometer. Carefully remove pan from oven. Remove chicken to a cutting board, tent with foil, and allow to rest for 5 minutes. Slice chicken into 1/2-inch chunks.
Assemble: Heat tortillas according to package instructions. One at a time, dividing fillings evenly, mound chicken, rice, cheese, beans, and guacamole on one side of tortilla. Fold sides over filling and hold them in place. Starting from the filled end, holding sides in and carefully roll the filled end tightly over the rest of the tortilla forming a log. Set aside, seam side down, and roll remaining burritos.