In a large bowl, whisk together the pineapple juice, brown sugar, ketchup, soy sauce, chicken broth, minced ginger, and garlic until well combined. Reserve 1 cup in a separate bowl for basting. Add diced chicken to the marinade, cover, and refrigerate for 30 minutes.

Combine diced pineapple, mango, avocado, chopped cilantro, and lime juice in another bowl. Toss gently and sprinkle with sea salt.

Heat a grill pan over medium heat for about 5 minutes. Brush with oil. Remove chicken from marinade and discard unused marinade.

Grill the chicken for 6-8 minutes per side, flipping halfway. Ensure internal temperature reaches 165°F. Baste occasionally with reserved marinade.

Once cooked, let the chicken rest for a couple of minutes. Dice into bite-sized pieces and divide evenly among mini corn tortillas. Top with fresh salsa.

Serve immediately while warm and enjoy the tropical flavors.