Mix 2 tablespoons Grey Poupon mustard with 2 tablespoons red wine vinegar.
Whisking constantly, add 6 tablespoons extra virgin olive oil, until creamy.
Actually, I've been making it so long, I forgot about the red wine vinegar. I've always used organic apple cider vinegar. And Melissa D'Arabian shared a secret, that when making his vinaigrette, a Parisian cafe owner added a few drops of soy sauce as a secret ingredient. Here's that link.
You can always make it more complex, adding minced garlic, minced shallots, fresh herbs you love. I always return to the basic and enjoy it with champagne vinegar and even the subtlety of rice wine vinegar. Leave out the vinegar, add lemon juice and grate Parmesan. Variations and flavors are endless.
For my taste this simple recipe means I never have to buy a bottle of dressing.
Based on a recipe in HEARTBURN, by Nora Ephron