Preheat the oven to 190°C.
Cut the potatoes and bell peppers in half, the onion into wedges.
Put them in a roasting tray together with the garlic cloves and chilli, if used. Scatter the marjoram on top and drizzle with oil. Combine them well, then put the tray in the oven for about 25-30 minutes, until the veggies get tender.
Take the tray out, let the vegetables cool a bit, the remove their skin. Put the vegetable flesh and cooking jus in a saucepan. Add the stock and, using a stick-blender, process until you get a thick, creamy texture.
Add the chickpeas and the curry powder, then bring to the boil. Add more stock if it’s too thick.
Add the coriander leaves and blitz again for a few seconds to create a more textured effect.