Even if you aren't growing your own watercress, you can easily make a homemade vinaigrette. We never buy bottled salad dressing — it's just too easy to make our own, minus the preservatives that come in a lot of brands. So let us offer a quick primer... The Formula:
A basic vinaigrette is one part acid (vinegar, citrus juice) to three or four parts fat (olive oil, walnut oil). Occasionally we like our vinaigrettes tart, so we'll reduce the amount of oil. If you want a thicker, creamier consistency, up the amount of oil.
Start with a large bowl. We like to have plenty of surface area to move around in when we're whisking. First, whisk together the vinegar or other acid and any spices or seasonings, including salt and pepper. Then, slowly stream in your oil as you whisk vigorously. The mixture will emulsify and thicken, and you're finished.
A classic French vinaigrette has Dijon mustard in it, combined with red wine or champagne vinegar. Minced shallots taste great with that combination, too. Or, snip off some fresh herbs like tarragon or chives and throw them in.
For salads that have fruit in them, like the Rice and Mixed Greens Salad we posted earlier today, we prefer a balsamic vinaigrette with a little brown sugar.
Try subbing in grapefruit or orange juice instead of vinegar, and play around with different oils (like one of our favorites, roasted walnut oil).
The Easy Out:
It doesn't take much muscle to whisk a vinaigrette, but you can always make one by putting all of your ingredients in a (tightly sealed) jar and shaking. A blender works, too, and is especially helpful if you're making a fruit vinaigrette and need to purée the fruit first.
A plate of pretty leaves, even with little else on them, is divine when dressed with a good vinaigrette. The Mache, Frisee, and Radish Salad with Mustard Vinaigrette, above, from Epicurious, is a perfect example — aren't those radishes beautiful?
Try these vinaigrettes from our archives:
And if you want more help, read these instructions from Everyday Food at Martha Stewart.
Related: What Is an Emulsion?