Special Mustard Sauce

Ingredients

• 2  beef bouillon cubes 
• 0.5 cup butter 
• 0.3 cup cider vinegar 
• 3  egg yolks lightly beaten
• 0.5 cup mustard prepared
• 1 teaspoon salt 
• 0.5 cup sugar 

Equipment

• whisk
• double boiler

Directions

1. Combine butter and bouillon cubes in top of a double boiler.
2. Place over simmering water, and cook, whisking constantly, until butter melts and bouillon cubes dissolve. Gradually whisk in beaten egg yolks.
3. Add sugar and remaining ingredients; cook, whisking often, 20 minutes. Cover and chill.