Add 1 15-oz. can fire-roasted tomatoes , 2 Tbsp. chili powder , and 2 Tbsp. adobo sauce (use 1 Tbsp. if you're sensitive to heat) to saucepan, stir to combine, and bring to a boil over medium-high heat. Nestle 2 skin-on, bone-in chicken breasts into mixture, reduce heat to medium-low, and bring liquid to a simmer. Cover saucepan and cook until chicken is cooked through and shreds easily with two forks, 25–35 minutes.