In large bowl or ziploc bag, add chicken, olive oil, orange juice, lime juice, garlic, and spices. Rub marinade all over chicken and place in fridge for at least 1 hour or up to 6 hours.
Remove chicken from marinade and discard marinade. Preheat grill to 425-450°F or a pan to medium-high heat. Cook for 5-6 minutes per side.
Transfer chicken to plate and cover with foil, letting rest for 5 minutes. Dice chicken into cubes.
Grill some tortillas for about 30 seconds per side until charred and set aside.
While chicken is resting, combine the chopped tomato, onion, cilantro, jalapeño, lime juice and sea salt in a bowl and set aside.
Serve chicken on warm tortillas with diced avocado, pico de gallo, and some cheese if desired.