Drain the halloumi and cut it, lengthways and across the middle to make 4 thick slices. Pat each slice dry with some kitchen towel.
Mix together the harissa, honey, lemon zest and garlic granules. Spread this mixture evenly over the halloumi slices, place on a plate and cover. Leave to marinate for at least 30 minutes.
Make the yoghurt dressing. Mix the yoghurt, mint, coriander and lemon juice together. Cover and refrigerate until needed.
Spray a non-stick frying pan with low-calorie cooking spray and place over a medium heat.
Cook the halloumi slices for 1-2 minutes each side. The honey can catch quickly so keep a close eye on it.
Split the rolls and fill with mixed leaves and tomato slices. Place a burger on top and serve drizzled with some yoghurt and herb dressing.