Place a 1-quart saucepan over medium high heat and add 1 tablespoon of olive oil to the pan. Once the oil is hot, add the onions and habanero pepper and cook until the onions are translucent, about 3 to 4 minutes. Add the garlic to the pan and cook for 30 seconds. Deglaze the pan with the lime juice and vinegar. Bring the pan to a boil then reduce the heat to medium. Add the sugar, mustard, and 1/2 teaspoon of the salt to the pan. Continue to cook the barbeque sauce until the mangoes are very soft, about 5 minutes. Remove the pan from the heat and allow the sauce to cool for about 15 minutes. You can leave the sauce chunky like this, or puree the contents of the pan in a blender on low speed for 1 minute, if desired. Reserve the sauce until ready to use. Sauce will keep up to 10 days in a non-reactive air-tight container in the refrigerator.
Preheat a grill to medium heat. Season the grouper with the remaining 3/4 teaspoon of salt and the white pepper. Place the fish on the grill and cook for about 3 minutes then turn the fish 45 degrees and cook for an additional 3 minutes. Turn the fish over and cook for an additional 5 minutes or until cooked through. During the last few minutes of cooking, brush the fish with the sauce. Serve with a simple salad, if desired.
Yield: 4 servings