The real glory of the dish is the walnut parsley pesto. The light dressing pairs well with the crispy grilled skin on the fish, and brings out earthy flavors on the sweet and salty white fish. —Just Me and The Clams
Put the walnuts, parsley, lemon juice, anchovies, and olive oil in a food processor and blend until smooth. Set this aside in a condiment bottle, small bowl, or jar.
I recommend using a grill basket; the fish is very delicate. If you’re using one, wipe the basket with olive oil. If you’re going to go directly on the grill, wipe the grill bars lightly with oil.
Stuff the fish with the lemon and garlic slices. Grill on medium high for 6-8 minutes on one side. Then pull the basket off the grill, and use a plate to flip the fish over and slide them back into the basket to grill the other side. If you’re just using the grill, use a large spatula to delicately roll the fish over. The trick here is patience. Don’t mess with the fish until it is ready to be flipped or you’ll peel off pieces of the skin in the process.