Preheat the oven to 180°C fan/200°C/gas 6.
Tip the oil, onion, pepper, mushrooms, spices and salt into a large roasting tin, then mix well. Transfer to the oven to roast for 15 minutes.
Remove the tin from the oven, stir through the chickpeas, chopped tomatoes and cream, then return to the oven for a further 40 minutes.
Let the curry stand for 5 minutes, then taste and adjust the salt as needed.
Serve hot with rice or flatbreads.
VEGANISE: Omit the single cream and stir through several generous spoonfuls of coconut yogurt just before serving.
