Ingredients
Method
1.Preheat oven to 220°C/200°C fan-forced. Heat oiled large shallow baking dish in oven.
2.Make rosemary marinade. Combine ingredients in screw-top jar; shake well.
3.Combine onion, lemon, rosemary and rosemary marinade in large bowl; add fish, turn to coat in marinade. Place fish, skin-side down, in hot dish; top with onion mixture and prosciutto. Roast uncovered, about 20 minutes.
4.Divide onion mixture among serving plates; top with fish and coarsely chopped prosciutto.