There's nothing like a nice tuna and mayonnaise sandwich. But the overfishing of tuna might soon make your preferred lunchtime nibble a thing of the past. A hard-hitting documentary called The End Of The Line shows how intensive fishing is damaging the world's once-thriving marine environments. Species such as bluefin tuna are already endangered, but the skipjack variety that is often used for canned tuna could also be threatened in years to come. High-street stores and restaurants including Marks & Spencer and Pret à Manger are now addressing the problem. Here are a few alternatives to tuna so you can do your bit.
A smoked salmon sandwich with cream cheese and a sprinkle of lemon juice on wholemeal bread might be a classic, but it is still a little dull. Instead, try boosting the oily fish flavour of your salmon by mixing the cream cheese with a little dill, some crème fraîche and crushed capers. Spread it onto sliced sourdough bread, cover with salmon and top with a spoonful of fruity caramelised red onion relish to give it a lift. Alternatively, try a poached salmon sandwich. Break the flesh into small flaky pieces after poaching, lay it on lightly buttered brown bread and dress it with a tangy dressing of mayonnaise, English mustard and lemon juice. Garnish with watercress and serve.
Save on bread as well as tuna - have a traditional Danish open sandwich (or smørrebrød) with pickled herring. The open sandwich uses only one slice of bread, preferably multigrain rye bread or pumpernickel, as a base for your topping. You can buy rollmop herrings from most supermarkets, which need to be unravelled and placed on the buttered bread. Vigorously mix a pinch of mild curry powder with a large dollop of crème fraîche and a drop of sugar syrup, then slather it over your herrings. Top with some freshly sliced red onion, slices of boiled egg and some dill. The sight of all those great ingredients alone will make you realise why open sandwiches are such a great idea.
The prawn sandwich has suffered a bit of a slating in recent years. Not only is it regarded as old fashioned and unexciting, but it has also been associated with corporate football ticket holders who have little involvement with the true passions of the game. It's reputation as a limp and lifeless sandwich lacking in vitality can be rectified, however. Slice half a baguette lengthways, and spread on a mixture of cream cheese, lemon juice, mayonnaise, Worcestershire sauce and a drop or two of Tabasco. Arrange the prawns on top with a few thin slices of avocado. Mix some horseradish with some tomato ketchup until you reach the desired flavour, and spoon it on top. Sprinkle on some very thinly sliced spring onions. Now, that's a prawn sandwich that few people could ever accuse of being boring.
The beauty of smoked mackerel lies in its moistness. It's a naturally oily fish, high in omega-3 fatty acids (not to mention plenty of vitamin B). But unlike tinned tuna, the shrink-wrapped plastic packs ensure that the mackerel flesh is never dry, which means you can use less calorie-cursed mayonnaise in your sandwich filling. Try removing the skin of the mackerel, shredding the flesh with a fork and mixing it with a combination of mayonnaise and horseradish. If the mackerel fillets have been packed with peppercorns, you might not need to season, otherwise add salt and pepper. Sprinkle with lemon juice and a few watercress leaves. Serve on lightly toasted ciabatta bread with a few cherry tomatoes on the side.
Whether you choose crabmeat or crabsticks is a matter of personal taste and financial viability, but good results can be achieved either way. If crabmeat is on the menu (tinned or fresh), shred the meat and mix it up with some mayonnaise, finely chopped celery, lemon juice, cayenne pepper and roughly chopped unsalted pistachios. Spread the mixture onto lightly toasted, thickly sliced white bread and cover with ice berg lettuce. If crabsticks are all you can muster, don't despair. For a Japanese-style sandwich, take some sliced whole grain bread. Cut some crabsticks, fresh mango and romaine lettuce into strips, arrange on one slice of the buttered bread and smear the other slice with wasabi. How much wasabi depends on how much you want to forget the tuna.