Saute mushrooms and onions in half the butter for 5 minutes over
medium heat. Mix the stocks; add mushrooms and onions. Add crushed
sesame seeds and remaining butter; heat, stirring, until butter
melts. Add salt. Cook over low heat for 10 minutes. Cool slightly.
Stir in heavy cream. Do not allow to boil. Serve warm or cold, garnished
with chives.