Ingredients

1/4 cup butter
1 cup diced onion ( 1/4-inch dice)
1 1/2 cups diced leeks ( 1/4-inch dice), well rinsed
2 tablespoons flour
4 1/2 cups chicken stock
Bouquet garni (see note)
4 cups diced Idaho russet potatoes
1/4 cup heavy cream (optional)
Salt and white pepper, to taste
Optional garnishes: chopped chives, sauteed cabbage and bacon (as desired)

Melt butter in saucepan over medium-high heat. Lower heat; add onion and cook gently for 2 minutes. Add leeks and cook for an additional 6 or 7 minutes, or until onions are soft but not browned.
Add flour and stir for 2 minutes to thicken (making a roux), without browning. Add chicken stock and bring to a boil; add bouquet garni. Add potatoes and simmer over medium heat for about 45 minutes, or until potatoes are cooked thoroughly.
Remove from heat. Remove bouquet garni and discard. Season to taste with salt and pepper. Add cream if desired, and stir in. Serve hot (reheat over gentle heat after adding cream, if necessary).
Garnish with chives, cabbage or bacon, as desired. Makes 4 servings.

Note: To make the bouquet garni, use:

1 bay leaf
2 tablespoons chopped parsley
1 sprig fresh thyme or 1/4 teaspoon dried thyme
1/4 teaspoon black peppercorns

Directions

Tie ingredients in a small piece of cheesecloth, or wrap in foil pricked with small holes.