Do not cut off the bottom root, and leave on an inch or so of the stem above the beet to prevent bleeding. Cook until tender in boiling salted water. Rub the skins off, remove the tops and tails of the beets and slice them thin. Have ready in a double boiler a cup of cream or one of milk to which you have added a tablespoon of butter and put the beets in this. Rub together a tablespoon each of flour and butter, stir it into the cream, add pepper, salt, and a teaspoon sugar, simmer until the sauce thickens and serve.