FOOLPROOF MAKE-AHEAD MASHED POTATOES

Steps:

• Combine enough water to cover the potatoes (about 6 cups) with 2 teaspoons salt and vinegar in a large pot. Bring to a simmer over high heat, then reduce the heat and add the potato slices. Cook just below a simmer for 30 to 35 minutes, until potatoes are tender when a fork is pressed into a slice. Drain and run cold water over the potato slices to cool them. Let them stand in water in the pot and add some ice. (You want to make sure that the potatoes are cool through before you mash them. This will help prevent gluey potatoes.).
• Drain well. Mash with an old-fashioned potato masher or large fork or run them through a ricer (don't use the food processor). When you have mashed fairly well, slowly stir in the cream. Stir the remaining 2 teaspoons salt and the pepper into the half-and-half, then stir into the potatoes until they are a little moister than you want the final dish to be. Taste; if necessary, add salt and pepper.
• Spoon potatoes into a large casserole (about 2 quarts) and cover with foil. Refrigerate overnight or hold at room temperature for up to 2 hours.
• Preheat the oven to 325 degrees. Heat potatoes in the covered casserole for 40 minutes, then uncover and serve. Potatoes will stay hot for the entire meal.