Vanessa Zoll fell in love with the Japanese sweet potato pretty much by accident.

Two years ago she was shopping for sweet potatoes at the Lexington Co-op. Not because she liked the orangey roots, but because regular sweet potatoes fit the rigorous restrictions of the high-protein diet she followed as she trained for another marathon.

Zoll bought the wrong tubers -- and was thrilled by her mistake. The Japanese variety looked similar. Sliced open and roasted, though, the Japanese variety developed a delectable crust and a pleasing texture.

"I love them," said Zoll, a Buffalo mother of two and school librarian. Next to the plainness of her diet, they were dessert. "I adore them," she said. "I could eat them every day."

With the array of root vegetables available today at area groceries and farmers' markets, why limit yourself to familiar, mundane carrots and potatoes? From celeriac, which looks like an alien spore but adds a tasty twist to classic preparations, to the Japanese sweet potato and its kin, here's what you need to know about unearthing a new favorite for yourself.

Maybe the parsnip, with its intense carrot-celery flavor, will hit the spot. Discover the hidden sweetness in turnips or its cousin, the rutabaga.

There are actually several varieties of sweet potatoes available locally besides the standards: Japanese, New Jersey, and garnet yams, which are actually another type of sweet potato. They can all be roasted whole or in chunks, pureed with other root vegetables, or used as pumpkin stand-ins in pies.

Besides being grown underground, these root vegetables have much in common. Most are easy to store, keeping well in a cool, dark place. They can all be used in place of carrots and potatoes in soups and stews, and are well suited to slow cooker treatment, not falling to mush. Plus, in a pinch they can all be peeled, cubed, tossed with oil and salt, and roasted until soft and caramelized.

The Japanese sweet potato habit has stuck for Zoll, even though she's not training at present. "We're all looking for that magical food that will get us through the day," Zoll said of her fellow high-protein diet adherents.

Japanese sweet potatoes, Zoll's favorite, are slimmer than standard sweet potatoes, with faintly yellow insides.

Zoll splits them open lengthwise and places them on a foil-covered pan. She bakes them at 425 to 450 degrees for about 50 minutes, until they're browned on top and tender inside.

They're good hot or cold, Zoll said, but are especially good warm and crusty, straight from the oven.

New Jersey sweet potatoes are one of the sweetest types around, with light brown skin and white flesh.

Despite their name, Garnet yams are another sweet potato variety, with reddish skin and bright orange flesh. Use the recipe below to shake up Thanksgiving's sweet-potato-and-marshmallow tradition with a maple-glazed pan of garnets.

Yellow beets are one of the heirloom varieties available sporadically in produce sections. They are cooked like standard crimson beets, but because of their color are sometimes used in composed salads and vegetable carpaccios.

Parsnips are a carrot cousin that can be roasted, fried, steamed or mashed. Its assertive character is often called upon in recipes to flavor larger amounts of mashed potato, or a pot of soup.

Turnips are slightly bitter but sweeten with roasting, and in the company of other ingredients. They're made into pickles, and also sometimes made into gratins, baked with cream and cheese. They figure in a German dish called Himmel und Erde, or Heaven and Earth, which is simply boiled turnips, potatoes and apples mashed together, with butter and milk if you like.

A close relative is the rutabaga, a yellowish turnip cousin that's often sold larger, and sometimes waxed. Its sometimes strong flavor can be mellowed in the company of fruit, as in the slow-cooker recipe below.

Last, and ugliest, is celeriac, or celery root. The knobby root of a celery variety, it's sometimes shredded into slaw or served matchsticked in mustardy mayonnaise dressing for a classic French salad.

Like its subterranean friends, though, it's often boiled and mashed, helping -- as in the recipe below -- make a platter of mashed potatoes something special.

> Fruity Rutabagas

3 medium-sized rutabagas, peeled and chopped

1 large onion, thinly sliced

3 large apples, peeled, cored and chopped

2 pears, peeled, cored and chopped

1 cup water

Juice of 1 lemon

Salt and pepper, to taste

The night before, combine the cut-up vegetables and fruit in an airtight container, add the water and lemon juice, shake to combine, and store in the fridge.

In the morning, oil the crock of your slow cooker. Combine all of the ingredients in your slow cooker. Cook on low for 6 to 8 hours. Taste and adjust the seasonings.

(From Kathy Hester's "The Vegan Slow Cooker," Fair Winds Press, $19.99)

> Garnet Yams with Maple Syrup, Walnuts and Brandied Raisins

1/2 cup raisins

1/2 cup golden raisins

1/4 cup brandy

5 pounds garnet yams or other yams, peeled, cut into 3/4 -inch cubes

3/4 cup pure maple syrup

1/2 cup (packed) light brown sugar

1/4 cup ( 1/2 stick) unsalted butter

1 1/2 cups walnut pieces, toasted

Combine raisins, golden raisins, and brandy in small bowl; toss to blend. Let soak at least 30 minutes and up to 1 hour.

Cook yams in large pot of boiling salted water until just barely tender, about 8 minutes. Using large slotted spoon, transfer yams to baking sheet to cool.

Meanwhile, bring 3/4 cup maple syrup, 1/2 cup brown sugar and 1/4 cup unsalted butter to boil in heavy medium saucepan over medium heat, stirring until brown sugar dissolves. Boil 2 minutes.

Butter 15-by-10-by-2 inch glass baking dish. Drain raisins (reserve brandy for another use). Place raisins in very large bowl. Add cooked yams, then maple syrup mixture and toasted walnut pieces. Toss gently to coat evenly, being careful to keep yams intact. Transfer yam mixture to prepared baking dish. DO AHEAD: Can be made 2 hours ahead. Let stand at room temperature.

Preheat oven to 350 degrees. Bake yams uncovered until syrup is thick and bubbling, basting occasionally, about 55 minutes. Let stand 10 minutes and serve.

(From Bon Appetit, via

> Celery Root Puree

1 medium celeriac (about 1 1/4 pounds), cut into 1/2 -inch pieces

1 small Idaho potato (about 6 ounces), cut into 1-inch pieces

Kosher salt

1 Granny Smith apple, peeled, cored, and cut into 1-inch pieces

1/2 cup heavy cream

2 tablespoons unsalted butter

1 bay leaf

Freshly ground black pepper

Place the celeriac and potatoes in a large pot of salted, cold water. Bring to a boil. Boil for 10 minutes, then add the apple. Continue to cook until all are tender, another 10-12 minutes.

While vegetables are cooking, heat the cream, butter and bay leaf in a small saucepan over medium heat.

Drain the cooked vegetables and apple and return them to the hot, dry pot. Stir them over low heat for 2 minutes until they are dry. Pass ingredients through a food mill into a large bowl. Remove bay leaf from hot cream and butter mixture, and stir into puree until smooth. (Alternatively, you can puree the vegetables and apple together with the cream and butter mixture in a food processor.)

Season puree with salt and black pepper to taste. Serve warm.