My mother had a repertoire of soups she made from scratch. It wasn’t a huge list, just three strong, but that was perfectly sufficient. They were potato soup, celery soup, and beef soup with tomatoes and carrots. Unvaried, they nourished and succored through many a meal. Nostalgia factor aside, though, curiosity eventually led me to tinker with tradition.
When it comes to potato soup, there are seemingly countless variations to accommodate your culinary whim of the moment and what you have on hand. For instance, the standard Idaho russets can be swapped out for the more colorful, light yellow Yukon golds, as I did for the photo above.
For the onion element, leeks were not part of our family kitchen lexicon when I was growing up, but onions were, and mom would have used yellow onion. My own use of leeks in the soup stems from the now classic pairing of them with potato in Vichyssoise, a cold soup of French or American origin, it’s not clear which.
The celery, which became key for me as I explored potato soup possibilities, would not have appeared in mom’s version either. That would have been a separate soup with no potatoes and thickened with a roux. The thyme sprigs are my innovation; neither Vichyssoise nor mom’s potato soup sports any herb. And, unlike Vichyssoise, but just like mom, I serve the soup hot.
2 tablespoons butter
4 1/2 cups filtered water
1 medium leek, white and light green part, thinly sliced and well rinsed (about 2/3 cup)
1 pound Yukon gold, russet, or similar mealy potatoes, peeled and coarsely cut up into 1/2-inch chunks
2 celery ribs, coarsely chopped
2 sprigs fresh thyme or 1/8 teaspoon dried thyme
1 teaspoon kosher salt
1/2 cup half and half cream
1 tablespoon finely chopped inner leek or scallion top, or chives, for garnish
Freshly ground white pepper, for garnish
1. Melt the butter in a large, heavy pot over medium-low heat. Add the leek and 2 tablespoons of the water and cook until soft, about 5 minutes.
2. Add the potatoes, celery, thyme, salt, and remaining water and bring to a boil over high heat. Decrease the heat to maintain a brisk simmer and cook until the potatoes are mashable, about 20 minutes. Stir in the half and half, remove from the heat, and let cool until no longer piping hot, 15 minutes or so.
3. Remove the thyme sprigs if using them and puree the soup in batches in a food processor. Reheat in a microwave or on the stove top, ladle into individual bowls, and garnish each with the chopped leek top and white pepper.