Combine all remaining ingredients in a mini food processor. Process ingredients until smooth.
1/2 cup orange juice, 1/4 cup lime juice, 1/2 cup chopped onion, 1 large jalapeno pepper, 1/2 teaspoon lime zest, 1/2 teaspoon orange zest, 3 Tablespoons olive oil, 2 Tablespoons tomato paste, 1 teaspoon dried oregano, 2 teaspoons cumin, 2 teaspoons chili powder, 2 teaspoons garlic salt, 1/2 teaspoon black pepper
Pour the marinade over the chicken, flipping and moving chicken to ensure all parts are in contact with the marinade. Tuck chicken under the marinade as best you can.
Cover with plastic wrap and marinate in the refrigerator for 12 hours.
30 minutes before cooking, remove chicken from the marinade and pat dry with paper towels. Removing surface moisture prevents the meat from steaming and allows for a better sear and flavorful crust formation.
Prepare grill (or you can cook in a skillet on the stovetop) by preheating to medium-high (about 375-400F). Clean grill grates with a grill brush then apply a thin coating of high point oil using long tongs and a piece of wadded up paper towel dipped in the oil.
Place chicken breasts on grill and cook for several minutes without disturbing. Turn chicken over and cook several more minutes. Continue cooking until internal temperature reaches 165F.
Remove to a clear plate and cover with foil, let rest 5-10 minutes before serving.