Quarter the potatoes lengthwise and thinly slice. Chop the celery fine or, if using parsley root, grate.
Melt the oil(or butter) in a soup pot and add the potatoes, celery, onion, and bay leaves.
Cook over medium heat for 5-7 minutes, stirring occasionally. Raise the heat, add the wine, and let it reduce until syrupy. Add 1 1/2 cups parsley, 1 1/2 teaspoons salt, and the water; bring to a boil.
Lower the heat and simmer, partially covered, until the potatoes have broken apart, about 30 minutes.
Stir in the cream and remaining parsley and heat through.
Taste and season with more salt if needed. Add the pepper. Remove the bay leaves and serve.
Roast 2 heads garlic(with skin left on) that have been rubbed with olive oil, covered with foil(and add a little water to the pan), in a 350*F. oven for 45 minutes. Remove skins and add with the onions and potatoes. You may run the soup through a food mill if desired.
Boil 1 bunch greens(mustard greens are especially good) 10-15 minutes, drain, coarsely chop, and add to soup with 2-3 pinches of red pepper flakes. Serve with a few shavings of Parmesan cheese.