Simmer oysters in their own liquor over very low heat 5 minutes, or till edges curl and oysters are plump.
Melt butter in blazer pan of chafing dish, or in skillet.
Blend in flour.
Stir in broth.
Cook and stir till thickened.
Stir in cream; heat through.
Place hot water bath under blazer pan, if using chafing dish.
Add a little hot sauce to egg yolks; return to hot mixture.
Stir constantly till thickened.
Stir in lemon juice.
Sprinkle with parsley.
Serve on Toast Rings.