Step 1

Heat oil in a large pot over medium-high heat. Add onion and cook, stirring occasionally, until softened, about 5 minutes. Add garlic, chipotles, oregano and salt and cook, stirring, until fragrant, about 1 minute. Add tomatoes and their juice and chicken; bring to a simmer. Adjust heat to maintain a simmer and cook, stirring occasionally, until an instant-read thermometer inserted in the thickest part of a thigh registers 165°F, 20 to 25 minutes.

Step 2

Transfer the chicken to a cutting board and shred using two forks. Stir the shredded chicken back into the sauce.