Makes 10 cups
If the day after Thanksgiving finds you with leftover sweet potatoes and chicken broth, use them for this creamy, golden soup enhanced with fresh chives and crisp leeks.
Make ahead: The soup can be made up to 2 days in advance, covered and refrigerated. The leeks should be cooked just before serving. Adapted from a recipe by Terri Pischoff Wuerthner, a cooking instructor and food writer.
5 tablespoons unsalted butter
2 cups peeled, cored and chopped tart apples, such as Granny Smith or pippin
2 medium cloves garlic, minced
1 teaspoon dried thyme
1 teaspoon poultry seasoning
1 teaspoon kosher salt
1/2 teaspoon ground white pepper
4 cups mashed sweet potatoes
4 cups whole milk
2 cups homemade or no-salt-added chicken or turkey broth
1 cup thinly sliced leeks, white part only (from 2 or 3 medium leeks), rinsed well
1/4 cup chopped or snipped chives
Melt 3 tablespoons of the butter in a 4-quart saucepan over medium-high heat. When the foam subsides, add the apples, garlic, thyme, poultry seasoning, salt and pepper, and stir to combine. Reduce the heat to medium and cook for 10 minutes, stirring frequently, until the apples are golden brown and softened. Transfer to a food processor or blender and return the saucepan to the stove top (not over heat).
Add the mashed sweet potatoes to the food processor or blender, and purée until very smooth. (If using a blender, you might have to do this in batches.) Return the mixture to the saucepan, add the milk and broth, and cook over medium-high heat, whisking until the soup is thoroughly blended and lump-free. Bring it to a boil, then immediately reduce the heat to medium-low and cook for 20 minutes, stirring frequently and adjusting the heat so it is just barely bubbling.
While the soup is cooking, melt the remaining 2 tablespoons butter over medium-high heat in a medium skillet. Add the leeks and cook until they are golden brown and slightly crisped, 6 to 8 minutes, stirring often.
Serve the soup hot, sprinkled with leeks and chives.
Per 1-cup serving, made with plain mashed sweet potatoes: 230 calories, 6 g protein, 33 g carbohydrates, 10 g fat, 6 g saturated fat, 30 mg cholesterol, 300 mg sodium, 4 g dietary fiber, 16 g sugar