Heat the oil in a pan, add the onion and fry for about 5 minutes until it has softened.
Add celery, potatoes, curry, turmeric, ginger and bay leaf. Sauté for a few minutes, then add the broth and yogurt. Cover and simmer for 30 minutes.
At the end of cooking, add the turnip greens. Serve with Caciotta al Radicchio.