1. Peel and grate onion and ginger.
2. Mix onion, yogurt, olive oil, ginger, salt, cumin, turmeric, cinnamon, and chili powder. Coat chicken thoroughly and place in a dish.
3. Refrigerate at least 3 hours and up to overnight.
4. Preheat broiler on high and arrange oven rack so that chicken will be approximately 5 inches from the heating element.
5. Remove rind and seeds from melon and cut into 1 inch chunks. Remove peel and pit from mango and cut into 1 inch chunks. Juice lime.
6. Arrange chicken on the rack of a boiling or shallow roasting pan. Spread any leftover marinade over the top of the chicken.
7. Broil for 15 minutes, turning half way, until chicken is cooked through and reaches an internal temperature of 160F.
8. Gently toss melon and mango with peach jam, lime juice, and black pepper.
9. Let chicken rest 5 minutes before serving. Serve with melon salad.