2 Tablespoons butter
3 Large Leeks
1 lb. boiling potatoes (red bliss or Yukon gold) peeled and cut in 1/2-inch pieces
3 cups chicken stock
Small bunch of fresh thyme
Salt and pepper, to taste.
A few tablespoons milk or cream (optional)
Remove the roots and dark green leaves from the leeks. Slice in half horizontally, then into 1/2-inch pieces. Soak in a bowl of cold water, swishing around to remove any grit. Drain, and repeat.
In a large saucepan or Dutch oven, melt the butter over medium heat. Stir in the leeks, and cover. Reduce heat to medium-low. Sweat for 5 to 10 minutes – until soft, but not browned.
Add chicken stock, potatoes, thyme and salt – I use about a teaspoon – and a little pepper. Bring it up to a simmer, cover, and cook for 20 to 30 minutes, until the potatoes are tender.
Take the soup off the heat. It can be eaten now, as a chunky, brothy soup, or you can mash it as much or as little as you like, for varying degrees of creaminess. Use a potato masher, a wand-blender, or get really fancy and drag out the food mill. Thin with a little milk or cream if desired.