Set everything ready before cooking. For the oven, preheat it to 350°, and for the grill, prepare it for medium-high heat. Use a brush to clean the grate and then lightly oil it. 

Deal with pine nuts. On a rimmed baking sheet, toast pine nuts and remember to toss once. It’s recommended to cook for 5 minutes until it becomes golden brown. Next let it cool. 

Grill onions. Normally we spend 15-20 minutes grilling onions, until skins are blackened and onions have softened. During grilling you need to turn occasionally. Next transfer it to a platter and let it cool for 10 minutes. 

Deal with cooled onions. Split onions in half, and remove the outer peel and discard. Then you can separate onion layers into individual petals. Transfer petals into a medium bowl and further mix with pine nuts, capers, raisins, and vinegar. Finally season agrodolce with salt.  

Time to deal with fish. Before grilling, season fish with salt and then drizzle with ¼ cup oil. It’s recommended to grill one side of fish for about 3-8 minutes (3 minutes for mullet and 8 minutes for snapper), until fish skin is lightly charred and flesh is flaky ad opaque down to the bone. When time is up, turn the fish to the other side. You can place a metal spatula underneath fish, then lift and gently roll over onto the other side. For the other side, also cook for 3-8 minutes depending on fish type, until flesh is flaky and skin is lightly charred. You can tell fish is well done if a small knife slides easily through the thickest part of flesh. When grilling the fish, avoid turning it over before the due time. 

Transfer fish to a platter. Spoon agrodolce over and top with parsley and some red pepper flakes. Drizzle with oil and serve with lemon wedges. Time to savor the dish!

Original source from bonappetit.com