Mango BBQ'd-Grilled Swordfish

Heat a large heavy saucepan over medium heat, add the oil and onion and stir. Then let the onions caramelize, without stirring. Add the garlic and stir for about 1 minute. Add all of the remaining BBQ sauce ingredients, bring to a boil, then reduce the heat and simmer for 50 to 60 minutes, stirring occasionally, until you have a little over 3 cups sauce. Leave chunky or puree in a blender or food processor. Set aside to cool. Remove the swordfish steaks from the refrigerator and let sit for 30 minutes at room temperature before cooking them. Prepare an outdoor grill for grilling over medium-high heat or preheat a grill pan over medium-high heat. Grill the swordfish steaks for 3 to 4 minutes on the first side and 2 to 3 minutes on the second side, until browned on the outside and cooked through. Transfer to warm serving plates and spoon some of the mango BBQ sauce around the fish.