Chicken marinated in a Yucatán-style axiote (achiote) paste and slow-cooked until tender. This healthy, high protein chicken dish delivers earthy, citrusy flavors for a family dinner.
Juice the orange and lime, then combine their juices with achiote paste, minced garlic, olive oil, oregano, salt, and black pepper in a medium bowl to make the marinade.
Place chicken thighs in a large resealable bag or shallow dish; pour the marinade over the chicken, making sure each piece is thoroughly coated. Marinate for at least 1 hour, up to overnight in the refrigerator.
Slice the red onion thinly and layer it at the bottom of a Dutch oven or heavy skillet. Arrange marinated chicken thighs on top, pouring any extra marinade in as well.
Set the pot over medium-high heat, sear chicken for 2–3 minutes per side until lightly browned, then reduce to low heat. Cover tightly and cook for 50–60 minutes, basting occasionally and checking that the onions don’t burn.
Remove lid, increase heat to medium, and allow sauce to thicken for 5–8 minutes. Serve chicken hot with the carmelized onions and pan juices spooned over.