Soak the dried beans in cold water overnight, then drain and place in a sauce pan. Add plenty of cold water to cover, bring to a boil and add the onion, carrot and bay leaves. Simmer for 1 hour or until just tender. Drain, refresh under cold running water, and drain again discarding the flavorings. Season and set aside. Preheat the oven at 190 °C.
Dip the baby turnips in boiling water for a minute or so, then drain and refresh under cold running water. Peel the turnips thinly, cut into quarters and season with black pepper.
Marinate the chicken with lemon juice, garlic, thyme and bake covered in the oven for 25 to 30 minutes.
Meanwhile, put the white beans and the baby turnips in a sauce pan with the chicken stock and cream and bring to a boil. Simmer, uncovered, for 10 minutes or so, until the sauce is reduced by one-third. Check the seasoning and stir in the chopped herbs and truffle oil.
When the chickens are cooked, rest in a warm place for 10 minutes before serving. Strain off the pan juices into a small saucepan, heat until bubbling, then whisk in the white vinegar, olive oil, chopped chives and mustard.
Divide the turnips veloute and white beans into warmed serving plates. Serve the chicken on top and drizzle over the vinaigrette sauce to serve.