Combine the potatoes and 1 teaspoon of the salt in a large saucepan over medium heat. Cover the potatoes with water and cook until fork-tender, about 20 minutes. Drain.
Return the potatoes to the pan and, over low heat, stir them with a fork or wire whisk for about 2 minutes to dehydrate them. Add the cream, butter, garlic, and spinach. Stir to mix well. Add the remaining 1/2 teaspoon salt and the white pepper. Mix well. Serve immediately.
Yield: 4 servings