In a medium bowl, combine the diced mango, avocado, red bell pepper, cilantro, lime juice, and a pinch of salt. Stir gently to combine and set aside.
Preheat a grill or grill pan over medium-high heat.
Brush both sides of the chicken breasts with olive oil.
Season the chicken evenly with chili powder and salt.
Grill the chicken for 4–5 minutes per side, or until the internal temperature reaches 165°F (74°C).
Remove the chicken from the grill and allow it to rest for 5 minutes.
Top each grilled chicken breast generously with the fresh mango avocado salsa.
Serve immediately and enjoy this delicious Grilled Chicken with Mango Avocado Salsa.