Put the potatoes in salted water to cover and bring to a boil; adjust the heat so that the water bubbles, but not too rapidly, and cook until the potatoes are tender but not mushy, about 20 minutes. Meanwhile, warm the milk gently.

When the potatoes are done, drain them, mash them or put them through a ricer, and return them to the pot over the lowest possible heat. Add the milk and stir, then add the butter and stir until it melts. Beat with a wooden spoon or rubber spatula.

Remove from the heat, add the cheese, and stir until it melts (if the cheese is not especially ripe, you might have to do this over the lowest possible heat). Season to taste, then garnish with chives and serve.

For speed, peel the potatoes and cut them into chunks before cooking. But don't make the chunks too small—certainly not less than 1-inch cubes, and perferably larger—or the potatoes will become waterlogged as they cook.

One pound makes 4 adequate side-dish portions; but these recipes are easily doubled if you want more.

For super-smooth potatoes, use a ricer or a food mill. A potato masher or a fork will give you chunky mashed potatoes. Your choice.

Mashed potatoes can be made as long as half an hour in advance, then held over very low heat, or kept at room temperature and microwaved for brief intervals, stirring in between each, until hot. But what makes the most sense is to boil whole potatoes in advance, keep in cold water, then reheat them and finish the recipe at the last minute.