Tip the bulgar wheat into a large heatproof bowl or pan. Sprinkle in a little salt and top up with 150ml boiling water. Cover with a large plate and set aside for 15 mins to soak.
Peel the garlic and crush or finely grate into a small bowl. Spoon in the yogurt and add a pinch of salt and pepper. Stir well to combine, then set to one side.
Grate the orange zest into a separate bowl and squeeze in the juice. Pour in 1 tbsp oil and add a little salt and pepper. Stir well to combine.
Preheat your grill to medium. Trim the courgettes and aubergine and slice both into 1cm rounds. Peel the red onions and slice into thin wedges. Scatter the courgettes and red onion wedges onto a baking tray. Toss with 1 tbsp oil and a little salt and pepper. Slide the tray under the grill and cook for 4-5 mins, till the veg are lightly charred. Turn over and grill for 4-5 more mins.
Tip the grilled veg into the cooked bulgar wheat. Add the spinach and spoon the orange dressing over. Stir well to combine. Pile the salad onto a couple of plates and serve with spoonfuls of the garlicky yogurt.