Ingredients

• 6 large russet (baking) potatoes (about 3 1/2 pounds)
• 1 onion, chopped fine
• 3/4 stick (6 tablespoons) unsalted butter
• 8 flat anchovies, rinsed, patted dry, and minced
• 3/4 cup milk
• 1/4 cup heavy cream
• 1/4 cup thinly sliced fresh chives or scallion greens

Instructions

1. Peel potatoes and cut into 1-inch pieces.
2. In a steamer set over boiling water steam potatoes, covered, until very tender, 15 to 20 minutes.
3. In a large heavy saucepan cook onion in 4 tablespoons butter over moderately low heat, stirring, until softened. Add anchovies and cook, mashing them, until they dissolve, about 1 minute. Stir in milk, cream, and remaining 2 tablespoons butter and heat until hot but not boiling.
4. Force potatoes through a ricer or food mill into pan and stir until smooth. Stir in chives and salt and pepper to taste.