1 cup mayonnaise
1 egg (hard-boiled and finely chopped)
1 tsp dry mustard
1 tsp anchovy paste
2 tsp capers (small size)
1 tsp chopped tarragon leaves
1 tsp minced garlic

Add mayonnaise to mixing bowl and stir in egg. Stir in dry mustard, anchovy paste, capers, tarragon leaves and garlic. Stir until anchovy paste disappears.

This, and another from Dante's Down the Hatch, can be found in the book Secrets of Atlanta's Best Kitchens, pp. 46-51.