Melt butter in top of a double boiler over hot (not boiling) water.
Beat the eggs in a bowl with a rotary beater until lemon-colored, then blend
in sour cream, salt, pepper and rosemary. Pour the egg mixture into butter in double
boiler. Cook over medium heat, stirring to keep the mixture from sticking to the
bottom of the pan as the mixture sets. Cook until as firm as desired. The eggs need
to be done but still soft and fluffy.