Fresh salad greens deserve equally fresh dressing.

And a simple vinaigrette - a quick blend of oil and vinegar with seasonings - is the freshest and purest of them.

But vinaigrette, that most basic of dressings, the perfect complement to salads, can be so much more. It can serve as a marinade or full-fledged sauce with entrees as well.

At Marigold in West Philadelphia, executive chef Erin O'Shea has come up with some innovative vinaigrettes.

Inspired by the flavor of smoked salmon, which led to thoughts of fried green tomatoes, O'Shea came up with a buttermilk vinaigrette that ties together those two favorite foods on the plate.

"I kept thinking of buttermilk, but I needed some fat to bring out and balance the tang, and that is how the buttermilk vinaigrette came about," O'Shea said.

"It's a great accent to the tomatoes and the smokiness of the salmon." And it works just as well with plain seared salmon fillets, the chef says.

O'Shea's menu of Southern-style foods with contemporary flair includes a unique raisin vinaigrette inspired by her memories of carrot-raisin salad, a dish prevalent at family functions when she was growing up.

"It's a very '70s salad, so I decided to update it," O'Shea said. "And this is where it led me."

After reformulating the salad ingredients as a viniagrette, she also rethought its use, drizzling it over a juicy pork chop and white beans as a finishing sauce. Indeed, vinaigrettes have virtually unlimited seasoning potential - from savory herbs to sweet fruits, with almost every acidic edible eligible to assume the "vinegar" role - in moderation.

Among the most memorable of the genre is the green goddess vinaigrette from food goddess Alice Waters, who created a lighter, brighter version of the original classic dressing at her Chez Panisse using white vinegar and egg yolks instead of mayonnaise.

At Jasper in Downingtown, chef/owner Nick DiFonzo takes pride in creating some of the area's most interesting "house" salads, which come with each entree and change weekly.

One recent salad selection that drew raves from tasters at Jasper featured the chef's champagne pear vinaigrette on field greens, shaved fennel, carrots, walnuts and diced pears. Champagne vinaigrette is one of the dozen or so basics in DiFonzo's repertoire of favored dressings.

Vinaigrettes also get their due in Raising the Salad Bar by Catherine Walthers (Lake Isle Press, $19.95), which offers a wide range of recipes, including the basic lemon and Dijon dressings below.

For all the variety, vinaigrettes start with a pretty much standard three-to-one proportion of oil to vinegar (though some favor a four-to-one ratio) plus salt and pepper to taste. Master that and you can move on to those limitless options "to taste."

Extra-virgin olive oil is considered the ideal base, but flavorful nut oils and neutral canola or grapeseed oil, even toasted sesame oil for an Asian twist, can vary the mix.

Start with a good white or red wine vinegar or a rich balsamic vinegar. From there you can substitute fruit vinegars, rice vinegar, or, stretching the name vinaigrette slightly, freshly squeezed lemon or other citrus juices.

Who doesn't love lemon or raspberry vinaigrette?

Flavorful additions, minced or pureed, include shallots, garlic, anchovies, olives, sun-dried tomatoes, grated citrus zest, diced tomato and such.

A binding agent or emulsifier - a little mustard or egg, or mayonnaise, a dressing already emulsified - will help hold normally incompatible ingredients (think oil and water) in suspension for an hour or so, long enough to serve.

If the mixture does separate, whisk it together again before serving. Blenders, processors and special utensils aside, a fork is all you need.

Then comes the fun part - using a custom vinaigrette not just to moisten greens but also as a light sauce or marinade for fish, seafood, chicken, even beef. Argentine chimichurri is, after all, just a thick herb vinaigrette.

---

Buttermilk Vinaigrette

Makes about 2 cups, up to 16 servings

1/2 clove garlic, minced

1/4 cup apple cider vinegar

1 cup light buttermilk

2/3 cup real mayonnaise

1/4 cup sour cream

2 tablespoons minced chives

1. Combine the garlic and vinegar; let stand 20 minutes to allow the garlic flavor to bloom.

2. In a separate bowl, whisk the buttermilk, mayonnaise and sour cream together. Gradually whisk in the vinegar mixture, then the chives and salt and pepper to taste (usually very little is needed).

Note: This dressing was designed to marry the flavors of the lightly smoked salmon and fried green tomatoes sometimes served at Marigold. It works well, too, with plain seared salmon, as well as with a simple green salad.

Per serving: 81 calories, 1 gram protein, 1 gram carbohydrates, 1 gram sugar, 8 grams fat, 5 milligrams cholesterol, 68 milligrams sodium, trace dietary fiber.

---

Champagne Pear Vinaigrette

Makes about 2 cups, up to 16 servings

Port wine and water

3 firm ripe pears, peeled and cored

1/3 cup champagne vinegar

1 tablespoon fresh tarragon

2 cinnamon sticks

6 whole cloves

6 whole allspice

3 tablespoons honey

3 tablespoons brown sugar

1/3 cup walnut oil

1/3 cup grapeseed oil

Salt and pepper to taste

1. In a medium saucepan, bring equal parts port and water (enough to cover the pears) to a simmer with the tarragon, cinnamon, cloves, allspice, honey and brown sugar. Poach the pears until tender enough to pierce easily with a knife but not soft. Remove pears to cool. Strain the liquid; discard spices. Reduce liquid to the consistency of light syrup. 2. In blender, combine one pear, the vinegar, and ½ cup of the poaching liquid. While blending, add the walnut and grapeseed oils in a slow, steady stream. Season with salt and pepper to taste. Adjust seasoning to taste, adding more poaching liquid for a sweeter dressing.

Note: At Jasper, this dressing recently was served over mixed field greens, arugula, shaved fennel, carrots, walnuts and the remaining two pears, diced.

Per serving: 131 calories, trace protein, 11 grams carbohydrates, 8 grams sugar, 9 grams fat, no cholesterol, 2 milligrams sodium, 1 gram dietary fiber.

---

Raisin Vinaigrette

Makes about 2 cups, up to 16 servings

1/4 cup small-dice carrots (1/4-inch dice or smaller)

1 tablespoon vegetable oil

Salt, to taste

1 cup seedless raisins

2/3 cup apple cider vinegar

½ cup water

½ cup grapeseed oil

Juice of ½ lemon

2 tablespoons chopped

flatleaf parsley

1. Saute the carrots in vegetable oil until barely tender, not soft. Add salt to taste, starting with very little until you find the right amount to bring out the sweetness of the carrots. Transfer the carrots to a plate to drain; reserve.

2. In a small sauce pot, bring the raisins and vinegar to a boil. Simmer for 2 minutes. Remove from heat and cool to room temperature. When cool, put the raisins and water in a blender; mix smooth at medium speed.

3. Slowly add the grapeseed oil and lemon juice.

4. In a separate bowl, combine the vinaigrette mixture with the carrots and parsley. Taste, adjust for more lemon or carrot, as desired. (This is a strong-flavored vinaigrette. You may add a little water to thin it, if desired, without really diluting the flavor.)

Note: At Marigold, this sauce is served over double-thick pork chops that have been brined, breaded, pan-fried to brown then finished in a 350-degree oven and served with white beans cooked in a hambone-and-vegetable stock.

Per 2-tablespoon serving: 96 calories, trace protein, 8 grams carbohydrates, 6 grams sugar, 8 grams fat, no cholesterol, 3 milligrams sodium, trace dietary fiber.

---

Herbed New Potato Salad With Dijon Vinaigrette

Makes 6 servings

For the Dijon vinaigrette:

2 tablespoons apple cider vinegar

1/4 cup olive oil

2 tablespoons Dijon mustard

Salt and pepper to taste

2 tablespoons each: freshly chopped chives, parsley and dill

For the potato salad:

2 pounds new potatoes (red, purple, fingerling or such)

1. For the vinaigrette, in a small bowl, whisk together the vinegar, oil, mustard, salt and pepper, then add the herbs.

2. For the potato salad, bring the potatoes to a boil in a large pot of cold water. Reduce heat to medium; cook uncovered until potatoes are tender and easily pierced with a knife, 10 to 15 minutes. Remove from heat; drain. Let cool enough to handle, about 5 minutes.

3. Cut the warm potatoes in half; place in a serving bowl. Add the vinaigrette. Toss gently and serve.

Per serving: 198 calories, 5 grams protein, 25 grams carbohydrates, 3 grams sugar, 9 grams fat, no cholesterol, 126 milligrams sodium, 3 grams dietary fiber.

---

Lemon Dressing (Vinaigrette-Style)

Makes 4 servings (6 to 7 tablespoons)

2 tablespoons freshly squeezed lemon juice

1 medium clove garlic, finely minced

4 to 5 tablespoons olive oil

Salt and pepper to taste

1. In a small bowl, combine the lemon juice and garlic.

2. Slowly whisk in the olive oil until mixture is creamy.

3. Season with salt and pepper, to taste.

Note: This dressing is suggested for a classic salad such as arugula with sliced avocado and shaved Parmesan cheese.

Per serving: 122 calories, trace protein, 1 gram carbohydrates, trace sugar, 14 grams fat, no cholesterol, trace sodium, trace dietary fiber.

---

Green Goddess Dressing (Chez Panisse)

Makes about 11/2 cups, up to 12 servings

1 small shallot, minced

1 clove garlic, minced

1 tablespoon white wine vinegar

1 tablespoon lemon juice

2 tablespoons lime juice

1 large egg yolk at room temperature, optional

1/2 cup extra-virgin olive oil

1/2 ripe avocado

3 tablespoons minced parsley

1 tablespoon fresh tarragon

1 tablespoon chopped basil

1 tablespoon minced cilantro

1 tablespoon chopped chives

Salt & freshly ground pepper

1. In a small bowl, mix the shallot, garlic, vinegar and lemon and lime juices. Let stand 5 minutes.

2. In a medium bowl, whisk the yolk. Gradually add half of the oil in a drizzle, whisking steadily. Add 1 tablespoon of liquid from the shallot mixture, then whisk the yolk mixture into the remaining olive oil. Add the avocado and mash it in with a fork. Whisk in the remaining shallot mixture and the herbs. Season with salt and pepper.

Per 2-tablespoon serving: 104 calories, 1 gram protein, 2 grams carbohydrates, trace sugar, 11 grams fat, 17 cholesterol, 2 milligrams sodium, 1 gram dietary fiber.

---

Contact food writer Marilynn Marter at 215-854-5743 or mmarter@phillynews.com.