500g firm white fish fillets, defrosted if frozen, roughly chopped
400g cannellini beans, drained and rinsed
100g fresh breadcrumbs, plus 60g extra
2 eggs, lightly beaten
Finely grated zest and juiceof 1 lime
Salt and freshly ground black pepper
20g butter
1tbsp olive oil
6 burger buns, split
1 tomato, sliced
1 avocado, stone removed and flesh thinly sliced
4tbsp mayonnaise
1 Put half of the fish in a food processor with the beans, breadcrumbs, egg, lime zest and juice. Blitz until smooth. Add the remaining fish and pulse briefly until just combined. Season with salt and pepper.
2 Put the extra breadcrumbs on to a plate. Shape the mixture into six patties and press into the breadcrumbs to coat. Chill for 15min or until firm.
3 Heat the butter and oil in a frying pan over a medium heat. Cook the patties for 3-4min on each side or until golden and cooked through. Drain on kitchen towel.
4 Meanwhile, lightly toast the buns. Fill the buns with the tomato, avocado, fish patties and mayonnaise. Serve with fresh watercress and lime wedges, if liked.
These would be also delicious served with a tartare sauce. Just mix some chopped gherkins with mayonnaise and a squeeze of lemon juice.