Add 1 gallon of water to a stock pot. Next, add the orange juice, sugar, salt, ground cumin, ground coriander, and cilantro. Juice the oranges, lemons, and limes into the stock pot and mix thoroughly. Be sure to keep the fruit rinds.
Pat the chicken thighs dry and trim off the excess fat & skin. Place them in a stock pot. Toss the orange, lemon, and lime rinds in as well.
Cover and place in the refrigerator for 12-24 hours.
Heat the grill to 400-425° using medium heat.
In a small bowl, combine the ground cumin, ground coriander, dried cilantro, garlic powder, onion powder, salt, and pepper. Mix well.
Take the chicken out of the marinade. Liberally season both sides of each chicken thigh with the seasoning mix.
Place the chicken thighs on the grill skin-side down. Turn after 10 minutes to skin-side up. Turn it 2 more times after 10 minutes of cooking on each side, for a total of 40 minutes. Use a meat thermometer to test the chicken. Be sure to test close to the bone as this area takes the longest to cook. The temperature needs to be 165°.
Serve with rice and beans. Garnish with fresh cilantro.