Heat some oil in a pan and cook the red onion until it softens. Stir in the tomatoes and cook until they are just starting to break down.
Take the pan off the heat and leave it to cool slightly.
Make the dressing by mixing the yoghurt, harissa, honey and lemon juice.
In a large mixing bowl add the chickpeas, mint and parsley.
Add in the cooled onion and tomatoes, then pour in two thirds of the dressing and mix well.
Cut the halloumi into 0.5 cm slices. Fry it in a dry non stick pan until golden on both sides.
Toss the halloumi with the rest of the ingredients.
Plate it up, then grate over some lemon zest before drizzling over the remaining dressing.
Serve immediately.