Peel the vegetables. Cut the carrot and sweet potatoes into bite-sized pieces. Finely chop the onion and garlic.
Heat the oil in a large pan, then sauté the onion for 5 minutes. Add the garlic, stir for 30 seconds, then add all ground spices and tomato purée. Stir for a minute, then add the sweet potato and carrot bits. Stir for a minute, then add the passata and water, together with the bay leaf and stock cube.
Bring to the boil, cover and gently cook over low heat for about 15-20 minutes.
When the sweet potatoes and carrots are tender, add the soy beans and cook for another 5 minutes.
Stir in the coriander leaves, and season with salt and pepper to your liking.