Wash the carrots and trim off each end. Peel the carrots, using a swivel-bladed paring knife.
Cut the carrots in half or leave them whole and place in a large saucepan or casserole. Add water to cover. The water should be about one inch above the top of the carrots. Add salt and bring to a boil. Cook until tender but not mushy. Drain.
Put the carrots through a food mill or potato ricer and beat in the butter. Add salt, pepper, and nutmeg to taste.