Ingredients

  • 3 cups mashed potatoes
  • 1/4 cup whipping cream
  • 2 ounces parmesan cheese, finely shredded (about 3/4 cup)
  • 2 tablespoons extra-virgin olive oil
  • 8 large portabella mushroom caps (about 1 1/2 lbs. total), gills removed, halved and cut into 1/3-in.-thick slices
  • 1 large yellow onion (about 12 oz.), chopped
  • 3 large carrots (about 9 oz. total), peeled and chopped
  • 1 tablespoon chopped fresh rosemary
  • 1/2 teaspoon kosher salt
  • 3/4 teaspoon freshly ground pepper
  • 2 garlic cloves, chopped
  • 1/2 cup dry white wine
  • 3 tablespoons flour
  • 1 1/2 cups mushroom broth or reduced-sodium vegetable broth
  • Finely chopped flat-leaf parsley

Method

  • Preheat broiler to high with a rack in middle of oven.
  • Microwave potatoes, covered, until heated through, 3 to 4 minutes. Stir in cream an
  • Heat oil in a 10-in. cast-iron skillet over medium-high heat. Cook mushrooms, stirring occasionally, until softened and -liquid has mostly evaporated, about 10 minutes. Add onion, carrots, rosemary, salt, and pepper; cook, stirring often, until onions and carrots are tender, about 10 minutes. Stir in garlic and cook 30 seconds. Add wine and cook until completely evaporated, about 3 minutes. Sprinkle vegetables with flour; cook, stirring constantly, 1 minute. Still stirring, gradually add broth. Cook, stirring often, until thickened, 5 to 6 minutes.
  • Remove skillet from heat. Spread mashed potatoes over vegetables to completely cover them. Broil until lightly browned, 3 to 4 minutes. Sprinkle with parsley.