First make the chickpea salsa by mixing the first six ingredients together.
Put the couscous in a bowl and pour over the harissa and hot water. Set aside.
Heat the grill (broiler) or barbeque. Mix the garlic, lemon juice and olive oil and toss in a bowl with the aubergine, peppers and halloumi.
Cook the vegetables and cheese for a few minutes each side until nicely browned. If you are using the barbeque, it's a good idea to put the vegetables and cheese on a baking tray or well oiled sheet of foil. Keep an eye on the halloumi. It will cook quicker than the aubergine and peppers.
Gently fry the walnuts in the butter, then mix through the couscous with a fork. Spoon onto a plate and scatter over the vegetables and halloumi. Top with some fresh coriander(cilantro) and serve with the chickpea salsa.