- 3 pounds russet potatoes, peeled, cut into 1-inch cubes
- 2 cups crumbled creamy blue cheese (such as Bleu d'Auvergne; about 8 ounces)
- 1/2 cup (or more) whole milk
- 2 1/2 teaspoons chopped fresh rosemary
- Fresh rosemary sprigs (optional)
- Cook potatoes in large pot of boiling salted water until very tender, about 15 minutes. Drain well. Return potatoes to pot. Add cheese and 1/2 cup milk and mash until almost smooth, adding more milk by tablespoonfuls for desired consistency. Stir in chopped rosemary. Season to taste with salt and pepper. (Can be made 8 hours ahead; cover and chill. Rewarm covered with plastic wrap in microwave, stirring occasionally and adding more milk, if desired.)
- Transfer mashed potatoes to bowl. Garnish with rosemary sprigs, if desired.