Bens White Bean Soup

Bring beans to a boil in a pot with 3 cups water, reduce heat and cook covered for 2-1/2 hours. Sautee onion and celery in 1 - 2 tablespoons oil until transparent, add to beans with 5 cups water add cubed potatoes and mustard seed. Cook until potatoes are almost done. Blanch and peel tomatoes, dice and add to soup along with salt and pepper simmer 15 min. The soup should be creamy and filling and the mustard seed should puff up and provide little mustard explosions when you bite them. Looks like a milk based soup but it isn't.