Morton's Steakhouse Mashed Potatoes

Mashed Potatoes
Serves 6
5 pounds russet or all-purpose potatoes, peeled
1 cup (2 sticks) unsalted butter
1 cup heavy cream
1 cup sour cream
1 tablespoon salt
1 teaspoon freshly ground white pepper

Cut the potatoes into approximate 1 1/2 inch cubes and transfer to a large pot. Add enough cold water to cover the potatoes by 1 inch and bring to a boil over high heat. Reduce the heat to medium and simmer for 20 to 25 minutes, or until the potatoes are fork-tender. Be careful not to overcook. Immediately drain in a colander.

Meanwhile, in a saucepan, combine the butter and cream over medium heat, and cook until the butter melts. Do not boil. Set aside.

Transfer the drained potatoes to the bowl of an electric mixer fitted with the paddle attachment and mix on low speed for 2 to 3 minutes, or until the potatoes start to break up and blend together. You may have to do this in batches. Gradually add the sour cream and mix until combined. Season this with salt and pepper. (Alternatively, mash the potatoes by hand with a potato masher.)

With the mixer still on low speed, slowly add the hot cream-butter mixture. When all is added, increase the speed to medium and mix for 30-40 seconds, or until thoroughly mixed. Add more warm cream if necessary for the correct consistency. The potatoes should not be completely smooth.