Vinaigrette

The traditional French vinaigrette has only a few ingredients. Dijon mustard, olive oil, red wine vinegar, salt and pepper. You can also add herbs or a scrap of chopped garlic or onion if you must.
I can't forget how to make vinaigrette: a few years ago there was a French listening test in which students had to listen to the ingredients and steps for making the dressing, translate, and then put them in the correct order. Because of the l'oignon and l'ail, some vinaigrettes ended up with lamb in them. There were a few more with chili, mayonnaise, and some other random ingredients. Some people said you had to boil the dressing: some people said it should be baked in the oven. Could be interesting! Anyway...

Dijon mustard (smooth and unseeded)
Red wine vinegar (not balsamic)
Good olive oil
Salt and pepper are optional

There should be about half to one teaspoon of mustard, and more oil than vinegar. Shake vigorously in a jar just before serving, and pour over a crisp green salad with fresh herbs.