1. Fill your kettle and boil it. Tip the bulgar wheat into a heatproof bowl. Pour in 300ml boiling water to cover it by 1cm, then pop a plate on the bowl to cover it. Set aside to soak for 20 mins. The bulgar will soak up the water and become tender.
2. Peel the onion and finely chop it. Warm a deep frying pan for 1 min, then add ½ tbsp olive oil and the onion. Season with a pinch of salt and pepper. Cook, stirring often, for 5 mins till the onion starts to look glossy.
3. While the onion cooks, trim the courgettes. Halve them lengthways and slice into 1cm-thick half-moons. When the onion starts to look glossy, add the courgettes. Cook, stirring often, for 5 mins till the courgettes starts to soften.
4. While the veg fry, peel and grate or crush the garlic. Halve the chilli and scrape out the seeds and white pith. Finely chop the chilli. Finely chop the parsley stalks, keeping the leaves to one side. Stir the garlic, chilli and parsley stalks into the veg. Add 1 tsp each ground cumin and smoked paprika. Cook, stirring, for 1 min.
5. Tip the tin of chopped tomatoes into the pan. Bring up to the boil, simmer for 2 mins and then take the pan off the heat. Taste and add a pinch more salt or pepper if you think it needs it.
6. Heat your grill to high. Coarsely grate the halloumi. If the frying pan is heatproof, scatter the halloumi over the courgette mixture. If not, transfer the courgette mix to a heatproof dish and top with the halloumi. Slide the gratin under the grill and cook for 8-10 mins till the halloumi is melted and golden.
7. While the halloumi gratin grills, finely chop the parsley leaves. Drain any excess water off the bulgar wheat.
8. When the gratin is golden, take it out from the grill and let it cool for a few mins. Serve the gratin with the bulgar wheat on the side, garnished with the chopped parsley.