Leek and Fennel Soup

1 medium to large leek
1 Tbs margarine (or butter)
1 head of fennel (fist size)
2 medium potatoes, peeled
2 14-oz. cans of vegetable stock (or 3 1/2 cups homemade will work)
3 Tbs dry white vermouth (or dry white wine)

Throughly clean the leek. Remove the very largest/toughest leaves. I use some of the green, as the soup will soften the leek leaves. Cut in half and slice 1/4" "half-rings". Saute in the butter over a low flame. If the butter isn't enough to "stew" the leek, add a couple of tablespoons of the stock. This keeps the butter to a minimum. Saute until soft but continue to stir as it browns some of the leeks quickly. Chop the fennel fine and add to the leeks. Coninue to saute and add a small amount of stock if it looks like it might burn. Chop the peeled potatoes into a mire poix size (basically as small as you can manage - about 1/4" dice) Add the potatoes and the stock to the pot. Simmer until the potatoes are cooked, about 20 minutes. As they cook and become soft, smash them lightly with the back of a spoon as you stir to make the soup creamy. Just before serving, add the vermouth and heat through.