Finely chop the parsley, mint and red onion. Mix in the lamb, peas, spices and salt until thoroughly combined. Shape into 4 patties, cover and chill for at least an hour.
Cook the peas according to cooking instructions on pack. Mix the bulgur wheat with the chopped herbs in a large bowl and add the tomato, spring onion, cucumber and peas along with the lemon zest and juice, garlic and olive oil. Mix thoroughly and season with salt and pepper.
To make the yoghurt, mix the harissa paste into the yoghurt and leave to one side.
Grill the patties until golden brown on both sides.
Serve immediately with the harissa yoghurt and tabbouleh.