Heat the oil and butter in the base of a tagine or a large, heavy-based saucepan over a medium heat, stir in the onion and garlic and cook for 1–2 minutes until they begin to soften. Stir in the aubergines and courgettes and cook for a further 3–4 minutes, then add the apricots, ras el hanout and sugar.
Stir in the tomatoes with half the herbs and bring to the boil, then cover, reduce the heat and cook over a medium heat for 30–40 minutes. Season to taste with salt and pepper, then garnish with the remaining parsley and coriander. Serve with a dollop of creamy yogurt and chunks of fresh, crusty bread if liked.