How to Grill Seafood Like a London Fish Market Don

If your seafood skills extend to chucking some barely-bigger-than-your-thumb-nail prawns in a curry or grilling a skinny salmon fillet to pep up your Tuesday night stir fry, it's time to take a long hard look at your fish-cooking game.

And what better time to begin channelling Cast Away than barbecue season? Seafood and summer go hand in hand—plus everything tastes better on the grill, especially when you're half a bottle of Pinot Grigio down and it's not even midday. And however much we will forever-and-always love barbecued ribs, it would be nice to know how to cook another kind of protein over the coals.

To uncover the secret to perfectly grilled fish, prawns, and shellfish, we asked CJ Jackson, head of the cookery school at London's Billingsgate Seafood, to share her go-to seafoods when firing up the grill.

As well as running a cookery school at Britain's largest indoor seafood market, Jackson has taught at the Cordon Bleu Cookery School in Paris and held a vice-principal post at Leiths School of Food and Wine. If she can't help us get better fishies on ours dishes this summer, no one can.

How to pick: I always go for raw prawns, not ready-cooked ones, and the big tiger variety. You don't want any that are too small as they're harder to peel. When they're really fresh, they should be a grey, translucent colour. Avoid any that have started to go black. They should have virtually no smell if they're fresh.

How to cook: If you want to skewer them, start by trimming off the feelers then make a little cut down the back to remove the gritty vein. I'd suggest marinating them in sesame oil and soy sauce before skewering and grilling. You don't want to marinate them in anything sugary because it'll make them burn more easily.

Personally, I'd leave the shell on and grill the prawns whole because it protects them from drying out and burning.

How to pick: You want to look for white, translucent fish. Buy a tail and have it filleted and trimmed to remove any membrane. There should be virtually no smell to it if it's really fresh.

How to cook: I'd skewer the monkfish or cook it as a whole piece. Wrapped in streaky bacon is a great way of stopping it from drying out and it might catch if it goes straight on the barbecue. It holds its shape very well unlike a lot of delicate fish that tends to break up on the barbecue.

How to pick: Scallops have a sweet, shellfish smell when they're fresh. I would buy them with the roe [the scallop's eggs] off because otherwise it'll pop and burn very easily.

How to cook: Scallops hold their shape well and marinating them in something might be useful to prevent them from drying out. A little bit of citrus and olive oil is all you need—something very simple because you've got a nice sweet flavour there.

How to pick: It's all about the colour. If they are very pink, they're not in good condition. Look out for white, translucent meat.

How to cook: With squid, you want to open it out as a whole sheet, score it, brush with oil and seasoning, and cook it directly on the grill. Cuttlefish is my personal favourite because it's got a great flavour and a good, cheaper alternative to squid. Score the head, season, and put it on the grill. It'll cook in about 40 seconds.

How to pick: A good tuna steak wants to be a really deep red. You don't want anything beige or brown, it's got to be bright red like a beef steak.

How to cook: Always oil the tuna steak well and season with salt and pepper before grilling. You need to have a grill which is really hot so that when you press the steak onto the barbecue, it will sear. You want to cook it for 30 seconds on one side, 30 seconds on the other. Cook again on each side and you're done.

Illustrations by Alice Duke.