Pre-heat the oven to 200C/220C Fan/Non- Fan
Put the tomatoes in the mixing bowl, add the oil, cumin, sugar, garlic, thyme, oregano sprigs, lemon zest strips, a pinch of salt and a good grind of pepper. Toss together with your hands.
Put the mixture in the cast iron dish, make sure the cherry tomatoes are nice and snug in the dish.
Roast for 20 minutes, until the tomatoes are beginning to blister and the liquid is bubbling, then turn the oven to the grill setting and grill for 5 to 7 minutes, until the tomatoes start to blacken on top.
While the tomatoes are roasting, mix the yoghurt with the grated lemon zest and 1/4 tsp salt, then return to the fridge.
Slice the Halloumi in thick slices of about ½ cm and fry them in a little bit of olive oil in a hot frying pan.
Once the tomatoes are ready, spread out the cold yoghurt on a large plate or shallow, wide bowl. Spoon the hot tomatoes on top, as well as the pan juices, lemon peel, garlic and herbs, and finish with the remaining oregano and chilli.
Serve at once with the toasted sourdough bread and slices of halloumi