Parsnip Pureé

To a medium pot, add 2½ pounds parsnips (peeled and coarsely chopped), 1½ pounds russet potatoes (peeled and coarsely chopped), 1 pound apples (peeled, cored, and coarsely chopped), 6 tablespoons unsalted butter, and ½ cup water. Cover and cook over medium heat, stirring occasionally, until everything is very soft, 45–50 minutes. Season with kosher salt and freshly ground black pepper, then use a potato masher or an immersion blender to mash the vegetables with their cooking liquid. Drizzle with melted butter before serving.