Leek and Potato Soup with Frizzled Coppa
Nothing humble about this soup, though it begins modestly enough with onions and potatoes, the humblest members of the veg kingdom. First, we coax deep flavor from the tops of the leeks for the stock. Then we transform cold, hard potatoes into a velvety, buttery puree. Cream is optional, but the frizzled Coppa is not. Enjoy this soup warm on a cool spring day, or serve it chilled as the weather warms. Just call it vichyssoise.
Directions
For the leek broth
Trim the leeks and discard any discolored or damaged outer leaves. Cut off the dark-green tops, reserving the white and light-green parts reserve to use in the soup. Roughly slice tops into 1-inch pieces and wash thoroughly. Put the tops, 4 cups water, and remaining broth ingredients in a Dutch oven or large pot and bring to a boil over high heat. The leek tops won’t sink until they soften a bit, so resist the temptation to add more liquid to try to cover them. Lower the heat to medium and simmer briskly for 20 minutes, stirring occasionally. Strain the broth through a mesh strainer into a large bowl and discard solids. You should have at least 6 cups of broth. Rinse out pot and dry.
For the garnish
While broth is simmering, heat the oil in a medium nonstick skillet over medium-high heat. Add Coppa pieces and stir until the meat is brown and crispy, 1 to 3 minutes. Remove to a paper-towel-lined plate to drain.
For the soup
Halve the reserved white and light-green parts of leeks lengthwise and cut into 1/2-inch slices, taking care to clean them well.
Melt the butter in the Dutch oven or large pot over medium heat. Stir in leeks, potatoes, onion, shallot, garlic, and salt. Heat, stirring, for 3 minutes, then cover the pot to steam vegetables. Stir occasionally until vegetables are softened, about 10 minutes. Do not let them brown. (Add a splash of water toward the end, if necessary.)
Add 6 cups of the leek broth and bring it to a boil. Simmer, partly covered, until the potatoes are very tender, 10 to 15 minutes.
Allow the soup to cool a bit. Working in batches, carefully puree the soup in a blender. Don’t fill the blender jar more than a quarter of the way on any batch. Keep the lid slightly ajar and covered with a thick kitchen towel while blending. When the soup is smooth, transfer it to the cleaned pot or a large bowl. When all the soup is pureed, taste and season with salt and pepper, if desired.
If using the heavy cream, return the pot to medium heat and stir in the cream to warm through.
Ladle the soup into warm bowls and garnish with the crisped Coppa.
Cook’s Notes
Leeks are often very sandy, so it’s critical to wash them thoroughly. Submerge sliced leeks into a large bowl filled with cold water. Use your hands to separate the layers and swish the greens through the water, rinsing off any grit or dirt. Lift the leeks out of the water, letting the dirt fall to the bottom of the bowl. Drying the slices in a salad spinner is a good idea if you have one.
