In a bowl, mix together the minced lamb with the grated onion, 3 minced garlic cloves, 4 tablespoons of chopped mint, ground coriander, and Dijon mustard.

Form the mixture into 4 burger patties and then chill them in the fridge until they are ready to cook

Preheat the grill on high, lightly oil the lamb patties, and then cook for about 4 minutes each side.

Place the halved burger buns under the grill for 30 seconds to 1 minute, until they are lightly toasted.

Spread a little of the mayonnaise sauce on the burger bun, top with a burger patty, a few slices of red onion, some more of the mayonnaise sauce, and some salad leaves.