Mix the minced meat with the curry paste and the coriander. Season to taste with salt and pepper.
Divide it into 4 equal sized balls, then flatten them slightly between your palms into at disk shape.
Brush the patties with olive oil on both sides.
Put the barbecue on, or heat a griddle pan, and cook the patties on each side for 5-6 minutes, according to your liking. Rest them for 5 minutes (under cover).
In the meantime, in another pan, fry the onions in a little olive oil until soft - if using a barbecue, brush the onion rings with some oil and put them on the griddle.
Cut the buns in half, then toast them till lightly charred.
Construct the burgers: put the lettuce on the bottom half of the bun, add some spicy tomato chutney, then the putty and top with the onion rings and the bun-half.
Serve warm.