Scotch Mustard Sauce

1 egg
1 cup mayonaise
1/4 yellow mustard
2 tablespoons white sugar

Crack 1 egg into a small saucepan.
With the heat on low, stir in mayonnaise, mustard and sugar.
When it just starts to boil, it's done.
Remove and let sit until cool, then chill for at least 10 minutes.