Soak the haricot beans overnight in water. The next day drain and rinse them well.
Place the ham in a large casserole pot, cover with water and bring to a simmer, then cook for 10 minutes before draining and discarding the water. Return the ham to the casserole along with the onions, garlic, haricot beans, bay leaf, thyme, pepper and Dijon mustard. Just cover with water, gently bring up