Mix together all the burger ingredients, except the oil. Divide the mixture into four and form into burgers. Cover and chill for 30 minutes.
Combine all the salsa ingredients in a bowl.
Brush the burgers with the oil and cook under a high grill or on a barbecue for about 3–4 minutes each side until cooked through.
Serve each burger in a bread roll with the tomato salsa and salad leaves.