Preheat the oven to 200°C, fan 180°C, gas 6.
Put the mince, onion, curry paste, 1 tablespoon of the coriander, the egg yolk and salt into a bowl and mix well. Shape into 4 patties.
Heat a frying pan over a medium heat. Fry the burgers for 2-3 minutes turning occasionally, to seal. Transfer to a baking tray and cook in the oven for a further 18-20 minutes , until just cooked through with no pink remaining.
Stir the remaining coriander through the mayonnaise. Cut the rolls in half and fill with the salad and tomato slices. Top with the burgers and a spoonful of the coriander mayonnaise.
Cook’s tip: as an alternative serving suggestion, make a mango salsa by mixing 1 diced ripe mango with 1 finely chopped red chilli, the juice of 1 lime and 1 tablespoon chopped coriander.