4 pounds russet potatoes, peeled, cut into 1-inch pieces
3/4 cup (1 1/2 sticks) unsalted butter
2 tablespoons coarse-grained Dijon mustard
1 1/2 cups (or more) buttermilk
Chopped fresh parsley
Cook potatoes in large pot of boiling salted water until tender, about 20 minutes. Drain. Transfer potatoes to large bowl.
Melt butter in medium saucepan over medium heat. Whisk in Dijon mustard. Remove from heat and whisk in 1 1/2 cups buttermilk. Using handheld electric mixer, beat potatoes until smooth. Gradually beat in buttermilk mixture. Season to taste with salt and pepper. Beat in additional buttermilk if dry. (Can be prepared 2 hours ahead. Cover and let stand at room temperature. Rewarm in microwave-safe bowl until heated through, about 5 minutes.) Sprinkle chopped fresh parsley around edge
Bon Appétit November 2000
Serves 10
