First, cook soaked borlotti beans in plenty of cold water to cover, till tender - about 1 hour. Let water evaporate a bit towards the end of cooking time, as borlotti beans tend to disintegrate into the cooking water.
Heat oil in a non-stick pot and saute the onion and garlic till golden. Add spices and cook for a minute.
Add remaining ingredients, cover pot and cook till vegetables are tender. Stir from time to time, and add more water if needed. Add beans and cooking liquid (beans should look a bit like very thick soup). Stir and reheat.