Gribiche Sauce

You'll need 1-1/2 (1.5) hard-boiled eggs; start them now if you have to.

Cut up as necessary on a large cutting board and keep aside:
  1/8 of a 300-gram jar of cornichons (really good ones)
  1/2 to 1 tablespoon fresh parsley
  1 tsp capers (they won't need chopped unless you're using the huge variety; I suggest the tiny ones for this)

Slice the eggs long-wise and put their 1-1/2 yolks in a medium bowl and set aside for a moment. Put the 1-1/2 whites on the cutting board and chop them.

Mash the yolks in the bowl with a fork with
  1/2 tsp French (not French's!) mustard
Then pour in and whisk:
  1/2 cup olive oil
Then whisk in:
  1 tablespoon white wine vinegar

Then stir in everything on your cutting board. Add salt and pepper to taste.

It won't be perfectly combined, but it will taste delicious over fish, vegetables, and also toast! It keeps about a week in the refrigerator and is one of my favorite hot-weather sauces. It's also great because it can take the place of mayonnaise without the risk of raw eggs.

adapted from the British edition of Je Suis Cuisiner (I Know How to Cook) by Ginette Mathiot -- a wonderful general cookbook if you have access to high-quality ingredients

(a re-posting from this site's predecessor, from when we lived where food poisoning was a terrible threat)