The French do some wonderful things with mayonnaise sauces, as you might suspect.
They make it with anchovies, for a wonderfully salty version; caviar, if you have more money than you know what to do with; lobster; watercress; and even chicken.
But I like mayonnaise aux crevettes, or shrimp mayonnaise best, and best of all it is crazy simple, and delicious.
You can use it as a dip, or a sauce for broiled fish or other seafood dishes. Add it to a fish taco and your family will rave.
1/2 cup boiled shrimp
1 cup of mayonnaise
Ketchup for color
Take the shrimp and 3-4 tablespoons of mayonnaise and blend together. Let it sit for 30 minutes. Sieve the mixture and whisk in the remaining mayonnaise. Add a few drops of ketchup for color, if you like. If you do not mind the texture of the mayonnaise before you sieve it, skip that step and just add the remaining mayonnaise.