Whisk together all of the marinade ingredients: 3/4 cup orange juice, olive oil, 1/3 cup lime juice, 1 teaspoon lime zest, honey, cumin, soy sauce, garlic and 1/4 cup cilantro in a medium-sized bowl. Remove about 1/2 cup (put in an airtight container in the fridge for later) and pour the rest into a large sealable bag.
Trim the chicken of fat and pound the breasts to even thickness or slice in half to get evenly sized breasts and place in the bag with marinade.
Place in the fridge for at least 3 hours making sure to flip the bag halfway through the time it is in the fridge. I recommend marinating for 6–8 hours.
Lightly oil the grill grate and then place the marinated chicken (discard marinade in bag) on the grill.
Cook for 10–12 minutes turning as needed (depending on the size of your pieces) or until chicken juices run clear and internal temperature is at 165°F.
As you flip and cook the chicken, brush it generously with the reserved 1/2 cup marinade frequently.
For the salsa, take the remaining 3 tablespoons orange juice, remaining 3 tablespoons lime juice, remaining lime zest, and remaining 1/2 cup cilantro and toss together.
When grilling the chicken, also grill the mango. Brush with oil and grill on one side for about 4–5 minutes at medium-high heat.
Chop the grilled mango and avocado into small bite-sized pieces. Add to the salsa with the diced red onion.
Drizzle the Cilantro Lime Dressing over the chicken breasts and top with a generous few spoonfuls of the salsa. Enjoy immediately.
For safe meat preparation, reference the USDA website.