The other day, a 13-kilo surmai — or seer fish as it’s known as here in Sri Lanka — arrived in a tuk-tuk. I am now at our holiday home on the beach, and local fishermen often bring their fresh catch for inspection.

The fish had been caught that morning, and had the clean smell of brine: this is the surest test of freshness. The other way to check is to look at the eyes: they should be bright and shiny. Dull, dead-looking eyes means the fish left the water a long time ago. Next, if you poke the skin, and the surface does not spring back to its original shape, it’s not a fresh specimen you have touched. And finally, the gills ought to be bright red. Our surmai passed all these tests, and was duly weighed and paid for.

As an island, Sri Lanka has a long coastline and is blessed with a wide variety of fish and crustaceans. We have a fishing village a few hundreds away on our beach, and the narrow local catamarans are dragged on to the sand. At night, we often watch dozens of lanterns bobbing on the sea as the fishermen put their nets out.

Over the years of spending much of the winter on the island, we have checked out a wide range of seafood restaurants. One of our favourites is the Nihonbashi, probably the best Japanese restaurant I have eaten at. Established by Dharshan Munidasa, it now has three outlets in Colombo, but the original near the Galle Face Hotel is the one we go back to again and again. The tuna sashimi is from fish selected that day at the harbour from among the catch destined for export. The Snow Garden is a tray full of crushed ice on which an artful display of different kinds of raw fish has been laid out to resemble a small garden.

A couple of kilometres away is Colombo’s latest foodie heaven, The Ministry of Crab. A joint venture involving Munidasa and the cricketing superstars, Mahela Jaywardane and Kumar Sangakara, the restaurant offers crabs ranging from small to Crabzilla that weighs in at over two kilos. Prepared in a variety of ways, you can choose between Pepper Crab, Chilli Crab and Baked Crab. Other offerings include Prawn Curry in a clay pot and grilled prawns.

Situated in the beautifully renovated Old Dutch Hospital — a structure dating back to 1677 — the Ministry occupies a huge, barrack-like hall with high ceilings. Diners sit at long tables on benches. The kitchen is open plan, and the cooks can be seen doing their stuff. The atmosphere is lively, but once your crab or prawns arrive, you concentrate on extracting and relishing the last bit of succulent, spicy meat.

At home, when we get an absolutely fresh tuna, I often prepare sashimi, removing skin, gristle and bones. What’s left is the delicious, dark red meat that is then sliced into thin, two-inch strips. These are placed on a large platter, covered with cling film and put in the fridge for an hour or two. Everybody at the table is given a small bowl with wasabi and soya sauce. True, my sashimi is not as elegant as a sushi chef’s, but then it costs a lot less, too, so we can eat large quantities without going broke.

If you want to serve raw fish, but aren’t quite sure about its freshness, here’s a trick I learned a long time ago. Once you have cut the fish, place the pieces in a colander and pour boiling water over it to kill any germs on the surface. Immediately then pour iced water to prevent it from starting to cook. Shake the fish dry, cover with cling film and put it in the fridge for a couple of hours to restore the colour.

To close, let me introduce you to one of my favourite recipes from my mother’s cookbook Pukao aur Khilao. Nandi, our wonderful Sri Lankan housekeeper and cook, spent around 10 years in Karachi as my brother’s children’s nanny. There, she learned Urdu and some of my mother’s recipes.

Ammi’s fish and tomato curry involves frying a teaspoon each of methi (fenugreek) seeds and powdered turmeric, red chilli, cumin and coriander in hot oil. Keep adding small quantities of water to prevent the spices from sticking. Once they have melded nicely, add largish pieces of a firm-fleshed fish like surmai that has been marinated in yoghurt, garlic and ginger, and cook for around eight minutes on a medium heat, depending on thickness. Take care not to overcook the fish. Towards the end, add halved tomatoes, and let them soften, adding their liquid to the gravy.

Serve with plain boiled rice, with one halved tomato placed on each piece of fish. Add a sprig of dill for colour.