My mother loved seafood more than anything, and her insistence on keeping all dishes that use it absolutely simple is a rule to which I have always adhered. The all-important flavor of the fresh fish must shine through — that was what she always told me! I like to serve langoustines with chunky chips and a crisp green salad dressed with a little olive oil, salt, and lemon juice.
Rinse the langoustines thoroughly, then cut each one open on the underside using a pair of sharp scissors and carefully remove and discard the black intestinal tract.
Put the langoustines in a shallow, non-metallic dish. Mix together all of the remaining ingredients except for the lemon wedges in a jug and pour the mixture over the langoustines. Cover and leave to marinate in the refrigerator for 30 minutes.
Preheat the oven to 350 degrees.
Lay the langoustines in a shallow roasting pan and roast for 10 minutes, basting frequently with the marinade and turning them occasionally, until they are cooked through. (Alternatively, cook on the grill rack over a hot grill.) Serve hot or cold with lemon wedges.