Step 1

In a large saucepan, combine 7 cups water, the chicken, a quarter of the onion, half the garlic, the carrots, bay and 1 1/2 teaspoons salt. Bring to a simmer over medium-high then reduce to low, cover and cook at a bare simmer. Cook until the chicken is opaque throughout and the thickest part registers 160°F, 20 to 30 minutes; flip the breasts once about halfway through.

Step 2

Using tongs, transfer the chicken to a large plate and and set aside to cool. Strain enough of the cooking liquid through a fine mesh strainer to yield 1 cup; discard the remainder. Using 2 forks or your hands, shred the chicken into bite-size pieces, discarding the skin and bones.

Step 3

In a 12-inch skillet over medium, heat the oil until shimmering. Add the remaining onion, the remaining garlic and 1 teaspoon salt. Cook, stirring, until the onion has wilted, 2 to 4 minutes. Add the oregano, cumin and cilantro stems, then cook, stirring, until fragrant, about 30 seconds. Stir in the chipotle chilies and adobo sauce, tomatoes and sugar. Increase to medium-high and cook, stirring often, until the tomatoes begin to release their liquid, 2 to 3 minutes. Add the reserved cooking liquid, scraping up any browned bits. Bring to a boil and cook, stirring often, until slightly thickened and clings to the skillet, 5 to 8 minutes.

Step 4

Stir in the shredded chicken, reduce to medium-low and cook, stirring occasionally, until the sauce clings to the meat, about 2 minutes. Taste and season with salt and pepper, then stir in the cilantro leaves.