Preheat the oven to 200'C / Fan 180'C / Gas Mark 4. Peel the potatoes and cut into large chunks (I usually go for halves or quarters, depending how big they are!).
Mix all of the marinade ingredients together in a bowl, stirring until mixed well.
Place the peeled potatoes, chantenay carrots and whole (unpeeled) garlic cloves in a large roasting tin and drizzle over the marinade. Stir well and then place in the oven for 30 minutes.
After 30 minutes, remove from the oven. Chop the halloumi into large chunks and scatter over the top of the vegetables.
Place back in the oven for another 30 minutes. Remove, stir through so that the veg and halloumi is evenly coated in the marinade, then serve. I love to squeeze the mushy garlic from it's skin and smear it over everything - yum!
Notes
Any leftover veg can be eaten cold the next day in a salad - the halloumi may need reheating as it will go hard.
You can stir the veg half way through the bake but be careful that the potato doesn't break up too much if it's stuck on the bottom! If so, it's best to leave it for the full cooking time.