Put the onion, garlic and potatoes into a roasting pan, scatter over the spices, season with salt and pepper and drizzle over the oil.
Roast for 15 minutes. Add the tomatoes, honey and 7fl oz water and roast for a further 15 minutes. Stir through the chickpeas and return to the oven for a final 10 minutes. Scatter with the herbs and serve with couscous.