I like the combination of the modest saithe and the more exclusive langoustine in this dish. And since I only use the shells to extract the flavor, it is not at all expensive. Try to get hold of ramsons (ramps or wild garlic) and serve the dish with ramsons purée. You can get it in well-stocked grocery stores, or you can order it fresh and make the purée yourself by pureeing it with neutral oil until it becomes a paste. Alternatively, use a combination of chives, scallion, and oil.
- 1Soak the fish in salted ice water for 15 minutes before cooking. That way the fish will become firmer.
- 2Wrap a kitchen towel around the langoustine shells and place them in a mortar. Crush the shells with the pestle. (No pestle or mortar? Crush the shells with the bottom of a heavy pan). Transfer the shells to a pot, and add water, butter, and potatoes. Let simmer with the lid on until the potatoes are tender. Stir gently a few times. Remove the potatoes and strain the sauce. Discard the shells.
- 3Heat butter in a hot frying pan and sear the fish with the skin down until the skin turns golden brown and cripsy. Flip after 4-6 minutes and cook for another minute, or until the fish is cooked through.
- 4Serve with ramsons purée, wild asparagus, potatoes and the langoustine sauce.