A Springtime Soup
Simple. Seasonal. And richly satisfying.
By Jane Lear
Some soups require a lengthy list of ingredients and plenty of time on the back burner; they are worth preparing in a big batch so you can freeze a couple of quarts for another day. Leek and potato soup, however, does not need this sort of commitment. It’s an uncomplicated, almost austere, old farmhouse soup that brings out the best in two vegetables, and it’s easily cobbled together on the fly.
I made it the other day when a trip down the grocery store’s produce aisle yielded leeks with very fresh, relatively crisp leaves and long, stout snowy white stems. (Note: The longer the stems, the greater the amount of chopped leeks will be.) As soon as I got home, I prepped those beautiful leeks, along with some burly russet potatoes, straightaway. Then, as the soup simmered, I stowed the rest of my haul and set the kitchen to rights. Filling and fresh-tasting, the soup was going to be exactly what we wanted after a brisk walk on the beach.
In terms of flavor, the leek is the most nuanced and refined member of the onion-garlic clan — a real treat on the palate after months of winter’s storage onions. It’s sturdy, too: Left whole, with roots untrimmed, leeks will easily last a couple of weeks in the refrigerator if you wrap them in a slightly dampened kitchen towel, then put them in a plastic bag.
As for the potatoes, they have varying starch and moisture contents depending on their type. Russets, the standard baking potato, are high in starch and low in moisture. So-called “boiling” potatoes are low in starch and, you got it, high in moisture. Yukon Golds, with their yellow-tinged flesh, strike a happy medium in both categories.
Each kind of spud will make a delicious soup in its own way, but typically, if using boiling potatoes, you’ll need to add more salt, because low starch means a higher proportion of natural sugars. I buy organic potatoes when I can find them, and often leave on the skins unless very thick; it seems a shame to waste them, and they add to the rough-hewn character of the soup. (At the other end of the spectrum is crème vichyssoise, in which the leek and potato mixture is puréed with cream and served cold. This soup, which has great finesse and timeless appeal, was created by the French chef Louis Diat, who became chef de cuisine at the New York Ritz-Carlton in 1910. In 1947, he joined Gourmet magazine as the in-house chef.)
Although some leek and potato soup recipes say to simmer the vegetables in chicken stock and/or milk, I stick with plain old water. It’s cleaner tasting, and if you like, you can thin as well as enrich the finished soup with some milk or cream.
Leek and potato soup hits the spot for lunch — feel free to add slices of cheese toast, made with a good cheddar — but it can be extremely satisfying for supper, too. Try embellishing it with a handful of greens — spinach or lemony-tart sorrel, for instance, or finely shredded kale — and serve it with a plate of thinly sliced brown bread, unsalted butter, and smoked or kippered salmon.
I first had this combination long ago in Scotland, in a gray stone cottage framed by neat rows of blue-green leeks, and to this day the meal conjures long twilights, a crackling fire in the hearth, and the distant boom of the surf. In case you find yourself wishing for dessert, a rhubarb oatmeal crisp is as good as it gets.
Leek and Potato Soup
In the recipe below, the method for cleaning the leeks may sound finicky, but it’s not a place to cut corners. Leeks always have a certain amount of soil embedded in their multitude of layers because of how they grow. Rain splashes the dirt onto the leaves, then washes it down to where the stem (which is actually lots of tightly bound leaves) begins. The particles of soil work their way deeper into the plants as they mature. So take your time! Put on some music and embrace the process.
About 4 large leeks
About 1½ pounds of potatoes
3 tablespoons unsalted butter
About 6 cups of water
Coarse salt and freshly ground pepper
Milk or cream to thin soup (optional)
Chopped fresh thyme, chives, chervil or tarragon for serving (optional)
1. Trim off the roots and dark green part of the leeks. Discard the tough outer leaf layer. Cut leeks in half lengthwise and thinly slice. Swish them around well in a bowl of cold water, then let them sit so that any soil or sand settles to the bottom of the bowl.
2. Scrub the potatoes and peel if desired. Quarter them lengthwise and cut into ½-inch pieces. Gently lift the leeks out of their bath with your hands and drain.
3. Melt the butter in a pot, add the leeks, and cook over low heat until the leeks are softened but not browned. Add the potatoes and water; season generously with salt. Bring to a boil, then reduce the heat and simmer, partially covered, until the potatoes are very soft, 30 to 40 minutes. They should be almost, but not quite, falling apart.
4. Smash some of the potatoes against the side of the pot to give the soup a thicker, smoother consistency, or, if you’re feeling ambitious, pulse a few ladles of soup in a blender, then return to the pot. Taste and think about adding some milk or cream. Or not. Tinker with the seasoning, adding a bit more salt and a few grinds of pepper. Ladle into bowls and scatter with chopped herbs if desired. OH
Jane Lear, formerly of Gourmet magazine and Martha Stewart Living, is the editor of Feed Me, a quarterly magazine for Long Island food lovers.