Heat your oven to its lowest setting. Put a dry frying pan on a high heat. Tip in the sesame seeds and toast for 2-3 mins till nutty smelling and slightly darkened. Scrape into a large bowl and leave to cool.
Zest the lemon into a small bowl. Peel and grate the garlic. Add to the zest. Pour in 2 tbsp olive oil and a pinch of salt and pepper. Set aside - this will dress the veg later.
Juice half the lemon. Pour into the bowl with the sesame seeds. Whisk in 1 tbsp oil and some salt and pepper. Peel and coarsely grate the carrots into the bowl. Quarter and core the apple. Coarsely grate it into the bowl and toss everything together (this stops the apple browning). This is your sesame slaw. Set aside for later.
Trim and cut the aubergine into 1 cm thick rounds. Trim the courgette and cut into 1cm thick diagonal slices. Peel and thickly slice the onion. Cut the halloumi into 8 pieces.
Place the frying pan back onto the heat. Get the pan smoking hot. Lay a single layer of the aubergine, onion and courgette into the pan. Cook, without oil, for 2-4 mins on each side till the veg is softened and charred. Transfer to a tray and keep warm in the oven. Repeat with the remaining veg.
Lay the halloumi slices in the pan and cook for 2-4 mins on each side till golden and beginning to melt. While the halloumi cooks, mix the sweet chilli sauce with the pot of yogurt. Season and add a squeeze of lemon to taste.
Toss the charred courgette, aubergine and onion slices through the lemon zest and garlic oil to coat. Stack the veg and halloumi into four piles. Serve with the sesame slaw, a dollop of chilli yogurt and salad leaves.