To prepare the marinade – using a blender combine the mango, lime, water, black pepper, salt and garlic and puree on high speed for about 30 seconds. Place the swordfish in a large resealable storage bag. Pour 1 cup marinade into the bag, close and refrigerate for up to 1 hour. Reserve remaining 3/4 cup marinade.
To grill the swordfish, preheat the grill to very hot*. Remove the swordfish from the marinade and pat dry. Brush a tablespoon of olive oil on the swordfish steaks and place on the hottest part of the grill. After 2 minutes, turn the swordfish steaks over with a spatula. Allow 3-4 minutes of grilling time on the second side, then move the steaks to a lower heat on the side of the grill. Cook for 2-3 minutes longer until cooked through. Brush the remaining tablespoon of olive oil on the mango slices and grill for 1-2 minutes over high heat on each side until lightly glazed and remove. Serve with reserved marinade drizzled on cooked swordfish and then top with grilled mango slices and garnish with fresh parsley.
*If using a grill pan, heat to medium high heat. Grill the swordfish for 4 minutes on one side, then flip and cook an additional 3 to 4 minutes. Follow mango grilling instructions above.
Source: Chef Allen Susser