Melt butter in 2-cup glass measuring cup (microwave high 60 seconds). Whisk in salt, mustard, hot sauce, egg yolks, vermouth and lemon juice. Combine thoroughly.

Microwave the mixture at 50% level, or medium, stirring every 15 seconds for 1 minute or until sauce is thickened. Whisk until thick and smooth. Serve immediately. Garnish with chopped chives if desired.