Cut the 3 pounds chicken breast lengthwise into thinner cutlets so they cook faster on the grill or in a pan. Season both sides with 2 teaspoons kosher salt and 2 teaspoons ground black pepper.
In a medium jug, whisk together the ¼ cup olive oil or avocado oil, ½ cup fresh orange juice, 2 tablespoon orange zest, ¼ cup fresh lime juice, and all the seasonings (2 teaspoons garlic powder, 2 teaspoons onion powder, 2 teaspoons Mexican oregano, and 1 ounce achiote powder)
Place the chicken in a bowl or pan and pour the marinade over it, making sure the pieces are mostly submerged. Cover and refrigerate for 2 hours or overnight.
Stir the chicken once or twice while it marinates so every piece gets coated. Remove from the fridge about 30 minutes before cooking.
Heat an outdoor grill or a grill pan over medium heat. Remove the chicken from the marinade and cook until charred and the internal temperature reaches 165°F. For pan cooking, use a heavy-bottomed pan over medium heat, 6-10 minutes per side.
Remove the chicken from the heat and let it rest for 5 minutes before slicing or serving.
Notes
Don’t marinate longer than 12 hours, or the citrus can break down the chicken.
If you don't have time to marinate it for the amount of time suggested, I do recommend at least giving it 20-30 minutes to soak in the flavor a bit.
Boneless skinless thighs or breasts both work. Thighs are juicier, breasts are leaner.
Use an instant-read thermometer to make sure the chicken reaches 165°F.
Let the chicken rest for 5 minutes before slicing so it stays juicy.
Storage & Freezing
Fridge: Store in an airtight container for up to 4 days.
Freezer: Freeze up to 3 months, thaw overnight in the fridge.
Reheating: Microwave, oven, or skillet until warmed through.