3 cups sliced leeks (white and tender green parts)
3 cups peeled and roughly chopped "baking" potatoes
6 cups water
1-1/2 tsp salt
1/2 cup sour cream, creme fraiche or half and half, optional
Large, heavy, covered stew pot or casserole.
PREPARE Leeks: Trim off the root ends, keeping the leaves attached. Cut off tops so the leeks are 6 to 7 inches long. Starting 1/2 inch from the root and keeping leaves attached, slit each leek lengthwise in half and then in quarters. Wash under cold running water, spreading the leaves apart to rinse off all dirt. Leeks can be braised whole or sliced crosswise into pieces for soup. (To julienne, cut leeks crosswise into 2-inch pieces, press leaves flat, and slice lengthwise into matchsticks).
BRING ingredients to the boil in a 3-quart saucepan. Cover partially and simmer 20 to 30 minutes, until vegetables are tender. Correct seasoning.
SERVE as is, or puree, and/or top each portion with a 1 or 2 TBSP of cream.
ONION AND POTATO SOUP: Substitute onions for leeks, or use a combination.
CREAM OF LEEK AND POTATO SOUP: After simmering the preceding soup, puree it and whisk in 1/2 cup heavy cream. Reheat to the simmer again before serving.
WATERCRESS SOUP: Add a bunch of washed watercress leaves and stems to the base soup for the last 5 minutes of cooking. Puree. Garnish with a scattering of fresh watercress leaves.
You can throw in any vegetables you might have on hand, suitably diced, for variety.