Fillet of fish traybake with peppers and broccoli

How to cook fish like a pro

From barbecued beauties to marinades in a jiffy, become the ultimate fish master-chef with these tips and tricks

How to cook fish like a pro

Fish is super easy to cook, although many of us tend to overcomplicate it, work ourselves up over it, or avoid cooking it completely.

To prove that it can be the simplest thing to prepare, and always tasty, we asked our food assistant Vanessa Graham to share her expertise around cooking fish, both in the kitchen and on the BBQ. 

Check out Vanessa’s top fishy tips, including some brilliant BBQ hacks and marinades-in-a-flash.

Keep an eye on it

“One of the most common mistakes people make is overcooking their fish,” says Vanessa. “Fish takes a lot less time than people think, but don’t worry, practice and experience will help you get your timing perfect.”

Look at the instructions on the packet if you're unsure how long your fillets or seafood need to cook for (most packs will clearly state their cooking instructions).

Brazilian-style fish stew

Or, if the pack doesn't have instructions, have no fear! Vanessa says it's super easy to serve sophisticated seafood.

“Use your senses to see when it’s done - touch it and look at it. The fish shouldn’t be bouncy and too tense, and it shouldn’t spring back. This is a sign you’ve overdone it. Instead, it should be soft and juicy, and make you want to tuck in!"

If you're really not sure, try cutting it open. Vanessa says, "If you’re not very confident with cooking fish, don’t feel ashamed of cutting it open to make sure it’s opaque all the way through - that's when you know it's perfect.”

Don't faff

Vanessa says another classic mistake is faffing around with the fish when it's cooking. "Fish is naturally fragile — try to avoid turning it and flipping it often, or it will start to crumble and break. One clean flip once the underside is cooked is all you need."

Salmon with watercress udon

Learn the basics

If you're a real novice when it comes to cooking with fish, Vanessa suggests starting with seafood like prawns and shellfish.

“Prawns are the easiest because they change colour, from translucent and slightly grey to a bright pink colour, when they’re cooked. They’ll also curl up, so it's easy to tell when they're done," she says.

"Shellfish like clams and mussels are also brilliant - make sure you've given them a good clean before adding them to the pot. When the shells all open up, you're done. Discard any that haven't opened; you don't want to risk it."

Moules marinières

When it comes to the easiest fish for homecooking, Vanessa recommends classic white fish fillets like sustainably-caught cod and haddock.

"White fish like cod and haddock are brilliant," she says. "The fish stays together nicely during cooking, it doesn't flake apart like other more delicate fish, so it's a lovely, trustworthy option."

super citrus

Vanessa recommends keeping flavours simple with a classic wedge of lemon, "Lemon, or any citrus, lends itself really well to fish. Squeeze some lemon juice over your freshly cooked fish to liven it up slightly and let that delicious flaky flesh sing.

"Garlic butter is also great with all seafood and fish," according to Vanessa

Getting saucy

“Asian flavours, like Thai curry paste, are a brilliant marinade to have up your sleeve. Keep a jar in the cupboard or fridge and spread a spoonful over the fillets before pan-frying for incredible flavours without too much hassle!”

Thai salmon coconut curry

Vanessa also praises poaching fish in a sauce to cook your fish perfectly every time. Poaching helps it retain its moisture, keeping it delicious. "Sauces work brilliantly with shellfish like mussels and clams, prawns and langoustine, and fish fillets alike!"

"Frozen fish fillets work brilliantly in curries, stews and sauces too," says Vanessa, "just pop the fillets straight into the sauce and add an extra minute or two to the cooking time, checking it's cooked through to the end."

Chuck another on the barbie

Barbecuing fish is a brilliant way to add some smoky flavours to complement that sweet, soft flesh. And although it needs a little bit more care and attention than classic sausages or burgers, it's so worth it for those amazing flavours.

“If you’re scared of your fish sticking to the bars or flaking apart and falling through the grill, place a piece of oiled foil on the BBQ and cook your fish on that," says Vanessa. "You’ll still get all of the smoky flavour from the coals but without any of the mess. It’s a great hack!”

Prawns and sturdier fish like tuna and salmon make brilliant kebabs, says Vanessa. “You can never go wrong with prawns on skewers, either. That stick makes the prawns a little bit easier to control, and you're less likely to lose some through the bars into the coals.”

Garlic prawn & pancetta skewers

Grill it good

If you're looking for the best fish to chuck straight on the grill, look no further than tuna and trusty salmon, says Vanessa.

"Salmon and tuna are sturdy and are more likely to hold their shape on the BBQ," she says. "Tuna is great because it’s meaty, and so you can treat it like a steak (but be aware that it cooks slightly quicker than beef steak!)"

Looking to perfect your fish skills this summer? Make sure to stock up on everything you need, from fresh fillets to scrummy shellfish, at Asda or pop into your local store.