Heat a small skillet over medium heat. Add ancho chili, caraway, coriander, cumin, and peppercorns. Cook until fragrant, about 5 minutes, shaking skillet often. Let cool.
Use a spice grinder or mortal and pestle to finely grind chili and seeds. Combine the spice mixture with salt, and rub it evenly over chicken.
Preheat oven to 400°F. Heat a large oven-proof skillet over medium-high heat. Add olive oil, swirling to coat the bottom of the skillet. Add chicken and cook until browned, turning once, about 10 minutes.
Remove chicken from skillet, and set aside on a plate. Add carrots and 1-2 tbsp orange juice to skillet, scraping up any browned bits stuck to the pan. Place chicken back in skillet, and transfer to oven; roast about 30 minutes, or until the internal temperature of the chicken is 180°F and carrots are just tender.
Drizzle remaining orange juice over chicken and carrots. Sprinkle with orange zest and cilantro just before serving. Remove skin if desired.