Heat the grill to high. Lay the fillets, skin side down, on an oiled baking tray. Mix together the breadcrumbs, butter, parsley, lemon zest and juice, and half the pine nuts. Scatter the mixture in a thin layer over the fillets, drizzle with the oil and place under the grill for 5 mins. Sprinkle over the remaining pine nuts, then serve with the lemon wedges and a potato salad.