To prepare the Mango Shrimp Salsa, heat the 2 tablespoons of oil in a medium skillet, over medium heat. Add the shallots and garlic. Saute 2 to 3 minutes, then add the shrimp. Saute 2 to 3 minutes more, or until the shrimp turns pink.
Add the fruit juices, chilies, tomatoes, and tomatillos. Cook just long enough to warm the tomatoes and combine the ingredients. Remove from heat and gently stir in the mango and cilantro. Season with the salt and pepper. Set aside.
Coat the fish with the 2 teaspoons of oil on both sides. Season with salt and pepper.
(Rub the grill with additional oil to prevent the fish from sticking.) Grill the fish on one side about 5 minutes or less. Using a metal spatula, carefully turn the fish and grill about 3 minutes or less, depending on the thickness of the fish.
Spoon the warm salsa over the grilled fish and garnish with sprigs of cilantro.