Preheat your oven to Combi Steam 350°F/180°C, 50% (medium) humidity.
Put the onion, garlic and 2 Tbsp oil into a large, shallow baking dish (mine is a 12"/30cm round cast iron) and stir to combine. Place the dish in the oven and cook until the onion has softened, about 10 minutes, stirring halfway through.
1 onion, 2 cloves garlic, 3 Tbsp olive oil
Put the tomatoes, sliced peppers, zucchini, oregano, cayenne, balsamic, sugar, salt and pepper into the pan and stir to combine. Cook for 15-20 minutes until the vegetables have softened slightly and the sauce is thick and fragrant.
28 oz can chopped tomatoes, 1 red bell pepper, 1 zucchini, 1 tsp dried oregano, ½ tsp cayenne pepper, 1 Tbsp balsamic vinegar, 1 tsp granulated sugar, 1/2 tsp kosher salt, 1/2 tsp ground black pepper
Take the dish out of the oven and give it a stir, then arrange the haloumi slices over the top of the sauce and brush with the remaining tablespoon of oil.
3 Tbsp olive oil, 13 oz halloumi cheese
Cook the dish for a further 20-25 minutes, until the halloumi is golden and softened. Scatter with the lemon zest and herbs, and serve hot or warm with flatbreads and a green salad.
1 lemon, 6 sprigs flat-leaf parsley, 3 sprigs thyme, crusty bread