The wifey-poo likes potato soup and every month or so she buys the ingredients for a recipe she's been using for years and follows to the letter. It's good soup, don't get me wrong, I eat it and enjoy it. The recipe is from an old cookbook though and produced during a time when Americans either didn't have access to a variety of quality ingredients or didn't care to eat food that was especially flavorful or complex. I recently took the day off as a personal reward for passing a certification exam and she asked if I would cook her the soup she liked for dinner that evening. Since I'm such a kind and generous soul, I agreed, but decided to give it a little flavor of the Spoon.
Finely dice the celery and onion and chop the rosemary from one sprig and 4-6 leaves of sage. Combine in a bowl and set aside to allow the flavors to combine while the potatoes cook.
Cut up your potatoes and boil them in salted water until they're soft, but not until they're mashing soft. Take a sprig of sage and rosemary, bruise them, then wrap them up in the cheese cloth. Tie the bundle closed with the string and drop it in the water with the potatoes. Leave one end of the string out, but don't let it dangle too close to the fire. The bundle is handy when you drain the potatoes, but isn't entirely necessary, it just keeps things tidy. It also makes you look suave like Rico in front of the ladies.
There exist two schools of thought on how to boil potatoes, each have their merits. My wife believes that you should add the potatoes to cold water, and then heat the water to boiling. She claims that this ensures even cooking and prevents the outside of the diced potatoes becoming too soft and crumbly while the insides are firm. I, on the other hand, like to add the diced potatoes to already boiling water.
My wife is right by the way, but what she considers a detriment I consider a benefit. I like the potato chunks to be a little crumbly and too soft at the edges when I add them to soup. As you stir the potato into the soup, the soft outside comes off and cooks into the liquid, thickening it and adding richness, especially to cream soups. It's a lifestyle choice though, far be it from me to tell you how to boil potatoes.
When the potatoes are cooked to the appropriate firmness, drain them and set them aside. Don't worry, they're plenty hot and won't get cold.
In a large sauce pan or steep sided skillet, saute the onion, celery, bay leaves, sage and rosemary until the vegetables are tender and translucent. Be careful of the bay leaves and don't break it up. Bay leaves are indigestible and brittle. Small bits that break off can tear the insides of your intestine. Add the flour, 1 teaspoon of salt and 1/2 teaspoon of pepper, and stir until the mixture is bubbly. Cook the roux until it reaches the desired color. The longer you cook it, the browner and nuttier it will get, and the chance that it'll burn increases. I like it just a little brown to bring out the flavor of the butter and reduce the flour taste.
When the roux reaches the desired color and consistency, add the milk, cream and chicken stock slowly but steadily, while constantly stirring with a whisk until it thickens slightly. Do not allow the liquid to boil.
Remove the bay leaves and stir in the dried mustard and Worcestershire sauce. You can use whatever Worcestershire sauce you want, but if you don't use Lea and Perrins, why even bother? Add the potatoes and stir for several minutes until evenly heated and well combined. Just before serving, chop up about 1 tablespoon of thyme and whisk it into the soup.
Salt and pepper to taste and serve hot, or cold. Frankly, it's good either way. It may seem like the heavy use of such strong herbs like rosemary and sage would overpower the soup, but by adding them early, and in stages, the flavors, while rich, are more subtle than you would suspect and create a complex layering of flavor. Enjoy, and wait for the accolades of those that sup from your efforts.