1. Preheat grill to medium heat, or between 350 to 450°F.
2. Trim excess fat from chicken, rinse and pat dry. If necessary, pound chicken to ½-inch thickness. Place chicken into a 1-gallon size resealable plastic bag. Add seasoning, oil and lemon juice to the bag. Seal bag and turn to thoroughly coat chicken.
3. Grill chicken over direct high heat for 6 to 8 minutes. Turn chicken and continue to cook for 6 to 8 minutes until cooked through. Transfer to a serving plate.
4. Combine salsa ingredients in a bowl; stir and season to taste with salt and pepper. (Can be made up to 8 hours ahead and refrigerated until ready to serve.)
5. Top grilled chicken with mango salsa and serve immediately.