MASHED POTATO CASSEROLE
4 pounds russet potatoes, peeled and cut into 1 inch cubes
1/2 cup half and half cream
11/2 cup low-sodium chicken broth
12 tablespoons unsalted butter ( or 1.5 sticks) cut into pieces
1 garlic clove, minced
2 teaspoons Dijon mustard
2 teaspoons salt
4 large eggs
1/4 cup finely chopped fresh chives
1. Adjust oven rack to upper-middle position and heat oven to 375 degrees. Bring potatoes and water to cover by 1 inch to boil in large pot over high heat. Reduce heat to medium and simmer until potatoes are tender, about 20 minutes.
2. Heat half-and-half, broth, butter, garlic, mustard, and salt in saucepan over medium-low heat until smooth, about 5 minutes. Keep warm.
3. Drain potatoes and transfer to large bowl. With electric mixer on medium-low speed, beat potatoes, slowly adding half-and-half mixture, until smooth and creamy, about 1 minute. Scrape down bowl; beat in eggs 1 at a time until incorporated, about 1 minute. Fold in chives.
4. Transfer potato mixture to greased 2-quart baking dish or a 13 x 9 inch pan. The potatoes will look very soupy when they are poured into the casserole dish. They will firm up and rise in the oven. For better browning and and impressive presentation, use a fork to make a peaked design on the top of the casserole. Bake until potatoes rise and begin to brown, about 35 minutes. Let cool 10 minutes. Serve.
5. Make Ahead: The baking dish with the potatoes can be covered with plastic and refrigerated for up to 24 hours. When ready to bake, let the casserole sit at room temperature for 1 hour. Increase baking time by 10 minutes.