Heat Olive Oil in a large sauté pan on medium heat. Add the Onions and cook until clear, about 5 minutes. Add Garlic and cook a minute more.
Add the Mango, Ginger, Raisins, Mustard Seeds, Red Pepper Flakes, Wine, Water (or Mango Juice), and Sugar. Stir together.
Bring to simmer, cover the pan, and cook on low for 30 minutes. Roast the Chicken
While the chutney is simmering, preheat oven to 400°F with rack in the middle position. Coat the bottom of the roasting pan with Olive Oil.
Rinse the Chicken thighs in water, and pat dry. Rub Olive Oil over the chicken pieces, sprinkle with Salt and Pepper.
Put Chicken pieces in roasting pan, and in the oven. Cook until the juices run clear when perforated, or when the internal temperature of the thighs is 170°F, about 30 minutes.
If the chicken pieces are not browned enough for you, you can finish them in the broiler for the last 5 minutes of cooking.
Remove chicken pieces from roasting pan.
Mix mango chutney with a little of the chicken drippings (without the fat).
Add salt to taste. Add a little sugar if too acidic.
Serve chicken with mango chutney sauce. Garnish with chopped Green Onions.