Starchy-turned-silky russet potatoes merge with traditional aromatic leek, onion, garlic, and celery soup bedfellows; purée with cream and simmer again with colorful chunks of waxy red potatoes and smoked ham bites to finish this luscious soup. A smattering of fresh thyme announces a delicate lemony finish. If fatback is not easily found where you live, substitute a few tablespoons of rendered bacon fat to get things started. Save the crisped bacon to crumble over the finished soup before serving.
Ingredients
- 4 (½-inch / 13-mm) wide strips fatback, well-rinsed of additional exterior salt
- 2 tablespoons unsalted butter
- 2 leeks, well-rinsed white base only, trimmed and cut into ½-inch (13-mm) dice (about 2 cups / 180 g)
- 1 medium onion, cut into medium dice (about ¾ cup / 113 g)
- 3 cloves garlic, smashed and coarsely chopped
- 1 large stalk celery, cleaned and cut into coarse ½-inch (13-mm) dice (about 2 cups / 200 g)
- 2 teaspoons kosher or sea salt, divided
- 1-½ teaspoons ground black pepper, divided
- 5 to 6 small to medium russet potatoes, peeled and cut into 1-inch (2.5-cm) dice (about 4 cups / 720 g)
- 1 to 2 tablespoons sweet vermouth
- 4 cups (960 ml) low-sodium chicken stock
- ½ pound (230 g) boneless smoked ham steak, cut into ¼-inch (6-mm) dice (about 2-½ cups / 450 g)
- 2 medium waxy red potatoes, unpeeled and well-scrubbed, cut into ¼-inch (6-mm) dice (about 2 cups / 360 g)
- 2 tablespoons finely chopped fresh thyme
- 1 cup (240 ml) half-and-half
- 1 cup (240 ml) whole milk
- 2 tablespoons unsalted butter
How to Make It
- Heat a 5-½-quart (5-l) heavy-bottom pot over medium heat. Add fatback and butter and heat together until butter is melted. Add leeks, onion, garlic, celery, 1 teaspoon salt, and ½ teaspoon pepper. Stir to coat. Continue cooking over medium heat until the vegetables have softened, about 5 minutes. Add the russet potatoes, vermouth, and chicken stock. Bring to a boil over high heat, reduce to a simmer over medium-low heat, and cook, uncovered, for 20 minutes, or until the potatoes are very tender and falling apart. Remove fatback and discard.
- Using an immersion blender or traditional blender, purée until very smooth. For a chunkier, more rustic version, a thorough mash with a manual masher is also an excellent option. In the same pot, add the ham, red potatoes, thyme, half-and-half, milk, remaining salt, and remaining pepper. Bring to a boil over high heat and reduce to medium low, cooking uncovered, stirring occasionally, until the red potatoes are very tender, about 20 minutes.
- Add butter just before serving and stir through until melted. Serve hot with fresh thyme sprigs for garnish. The soup stores very well covered and refrigerated for up to 3 days. Add extra cream or milk, as needed, to reheat.