To prepare the marinade, place the olive oil, juices, garlic, shallots, zest, and spices into a blender.
Blend the marinade on high for 1 minute, until smooth.
Reserve ⅓ cup of the marinade and pour the remaining marinade over the chicken, moving the pieces around to fully coat them. Cover the chicken and refrigerate for a minimum of 2 hours.
Place a large frying pan over high heat. Spray the pan with cooking spray.
Place the chicken thighs in the pan, skin-side down, and cook for 5 minutes, or until nicely browned.
Turn the heat down to medium-high, flip the thighs, and continue to cook for 4 minutes, or until the chicken reaches an internal temperature of 165 F.
Turn off the heat, remove the chicken from the pan, and allow the thighs to rest for 5 minutes.
Garnish with orange slices, lime slices, and cilantro, if desired, and serve with the reserved marinade as a dipping sauce.