
The shelled walnuts pictured here were gathered in a Clearlake, Calif. neighborhood, and those in the shell were grown at Kalikei Farm in Upper Lake, Calif. Photo by Esther Oertel.
A phone call to my mother inspired the dish I’m eating now, namely a rich, succulent roasted winter squash filled with butter, honey and some finely chopped walnuts. It’s the perfect meal for a chilly evening when one doesn’t wish to fuss much with dinner.
Other than the butter (which hails from nearby Sonoma County), all ingredients are Lake County grown.
The little Japanese squash is from one of my treks to Leonardis Organics in Kelseyville; the raw honey is produced by R. B. Landrum of Clearlake and was a summertime farmers’ market purchase; and the walnuts were a recent gift, gathered by a friend in her Clearlake neighborhood.
I love all manner of nuts, and walnuts are my favorite. They seem to go with everything, including my winter squash meal, adding a nice crunch and satisfying texture to the sweet softness of the dish.
Almost all walnuts cultivated in the U.S. are one variety or another of English walnuts, which in Britain are called Persian walnuts or common walnuts. These are native to an area from the Balkans eastward to the Himalayas and southwest China. The ancient realm of Persia is included in this swath of land, hence the name Persian walnut.
It is said that walnuts are the oldest tree food known to man, dating back to 7,000 B.C.
Walnuts were reserved for royalty in ancient Persia, and the ancient Romans greatly revered them, calling them Jupiter’s royal acorn, a reference to one of the most powerful gods in the mythology of their culture.
Walnuts were traded along the ancient Silk Road between Asia and the Middle East. Eventually ships carried walnuts throughout the known world, further spreading their popularity.
Because English merchant marines transported walnuts for trade to world ports, these beloved nuts became known as English walnuts. Ironically, walnuts were never grown commercially in England.
Another species of walnut, the black walnut, is native to North America, with varieties that grow in both the east and west. The Eastern black walnut grows wild throughout eastern North America, and the California black walnut, also known as the California walnut, is endemic to California.
Black walnuts were gathered and consumed by American Indians.
The shell is far more difficult to crack than the English walnut’s thinner one, and the extraction of the nut is also harder.
Black walnuts are harvested in the wild (with 65 percent coming from Missouri) and are shelled commercially for use in foods, particularly ice cream, baked goods, and sweets. Their taste is more robust than that of English walnuts.
Black walnuts are not generally cultivated; however, English walnuts are often grafted onto black walnut root stock to promote a hardier tree for commercial farming.
A lesser known species of walnut, also native to North America, is the white walnut, or butternut. Not often used in food, its light wood is utilized for furniture.
English walnuts flourish in California’s Mediterranean-like climate, something discovered by the Franciscan fathers who were the first to cultivate them here in the late 1700s.
Now the Golden State accounts for a full 90 percent of the nation’s walnut crop. 99 percent of these are grown in California’s Central Valley, with much of the remaining 1 percent grown in Lake County.

A variety of shelled and unshelled walnuts, including samples for tasting, graced Kalikei Farm's table at a 2011 Lake County Farmers' Finest market in Lakeport, Calif. Photo by Esther Oertel.
Lake County’s walnuts are particularly prized because of their lighter color. This is due to the county’s high elevations that bring cooler summer temperatures than in the Central Valley. Buyers pay a premium for the higher quality of Lake County walnuts.
According to the “Lake County Food Guide” at www.co.lake.ca.us, there were 2,160 acres of walnuts in Lake County in 2008, bringing more than a million dollars of income into the county. As with the county’s pear crop, much of walnut cultivation is giving way to winegrapes.
I love tossing walnuts in salads, pasta dishes, sauces, all kinds of baked goods, and veggies to add flavor and texture.
I add them to risotto and quiche, toss them with rice, sprinkle them on soup or yogurt, and combine them with dried fruit, spices, and honey to make a flavorful topping for creamy brie cheese.
They’ve been the star in miniature tarts, make a fine substitute for pine nuts in pesto, and are a must-have ingredient in homemade granola.
Toasting walnuts intensifies their flavor and I often take the time to do this before adding them to dishes.
My preferred method is to toast them in a dry sauté pan on the stovetop, stirring or tossing them to ensure even toasting.
They may also be roasted in the oven in a shallow pan, which takes a bit longer than the direct heat of a stovetop burner.
Be sure to watch them carefully in either case, as there’s a fine line between perfectly toasted and burned nuts.
One you begin to smell them they’re close to being done, so keep your eye on them like a hawk on a field mouse.
Rosemary walnuts are one of my favorite savory snacks and are very easily made. Combine walnuts, a handful of roughly chopped rosemary, and some olive oil (local, if you’ve got it) in a pan on the stovetop.
Go through the procedure described above for toasting the walnuts, adding salt and freshly ground black pepper to taste as you go.
Put them out at a party, store them away in a sealed container, or give them away as gifts. They’re good with a hearty Cabernet, and believe me, they won’t last long. You might want to hide a batch just for you.
If you’d like an interesting (and healthier, in my opinion) substitute for a traditional graham cracker crust, try one made with walnuts and a bit of brown sugar. I use about two tablespoons brown sugar to a few handfuls of walnuts for a subtly sweet crust. The sugar may be eliminated if the crust is for a savory dish, such as quiche or a mushroom pie.
Simply toss the walnuts (and the sugar, if you’re using it) into a food processor and pulse until the walnuts have become the consistency of fine crumbs. Be careful not to overdo it, as you may end up with walnut butter instead.
The high oil content of the nuts will make it easy to press into a pie pan, rendering added butter unnecessary.
And speaking of high oil content, walnuts should be stored properly or their oils may become rancid. Shelled walnuts should be kept in an airtight container in the fridge, or they may be frozen for up to a year.
Some people also store their unshelled walnuts in the fridge, but if kept in a cool, dry, dark place, they should be good for at least six months.
Walnut oil has a lovely taste and a light, delicate consistency. Its fresh flavor is short-lived, so is best when used quickly after opening. It makes a wonderful vinaigrette, especially when combined with Dijon mustard, red wine vinegar, and parsley, but is not good for cooking because of its low smoke point.
The health benefits of walnuts are copious, and scientific research indicates they improve bone and heart health, benefit cognitive function, positively impact those with diabetes, and protect against some forms of cancer.
Walnuts are one of the best plant sources of protein, and are rich in monounsaturated and polyunsaturated fats that have been shown to lower LDL cholesterol.
Walnuts have significantly higher amounts of omega 3 fatty acids than other nuts; in fact, a handful of walnuts provides as much of it as a serving of salmon.
They’re also rich in fiber, B vitamins, magnesium and antioxidants such as vitamin E.
One of my favorite flavor companions for walnuts is mushrooms. They’re wonderful together in my opinion, and today’s recipe incorporates both in a delicious stuffed mushroom hors d’oeuvre. These are always a crowd pleaser and are fun for holiday parties. (I always make a double batch.)
The best part about eating walnuts (next to their flavor and crunch) is knowing how good they are for you. Enjoy!

A young walnut aficionado is enthralled with a portable nutcracker at a 2011 Lake County Farmers' Finest market in Lakeport, Calif. She is assisted by Haji Warf of Kalikei Farms in Upper Lake, Calif. The nutcracker also cracks filberts, pecans, and almonds, and is manufactured by the Davebuilt Co. of Lakeport, Calif. Photo by Esther Oertel.
Mushrooms stuffed with walnuts and cheese
12 medium-sized mushroom caps
1 tablespoon olive oil
1 tablespoon unsalted butter
½ cup finely chopped yellow onion
2 tablespoon coarsely chopped walnuts
1 garlic clove, peeled
5 ounces frozen chopped spinach, thoroughly defrosted and squeezed dry
1 ounce feta cheese, crumbled
1 ounce Gruyere or Fontina cheese, crumbled
2 tablespoons minced fresh dill
Salt and freshly ground black pepper to taste
Remove the mushroom stems and save for another use. (They’re great in homemade vegetable stock and can be frozen for this purpose.) Wipe the mushroom caps with a damp paper towel and set aside.
Heat the olive oil and butter together in a small skillet over medium heat. Add the onion and cook, covered, until tender and lightly covered, about 20 to 25 minutes.
Preheat the oven to 400 degrees F.
Add the walnuts and garlic to the onion and cook for another minute. Add the spinach and cook for another five minutes, stirring constantly. Remove from heat and cool slightly. Stir in the cheeses, dill, salt, and pepper.
Arrange the mushrooms, cavity side up, in a baking dish. Divide the spinach mixture evenly among the mushroom caps.
Set the baking dish on a rack in the upper third of the oven. Bake until the filling is browned and the mushrooms are thoroughly heated, 8 to 10 minutes. Serve immediately.
Twelve mushrooms is typically three or four hors d’oeuvre portions.
Recipe courtesy of “The Silver Palate Cookbook” by Julee Rosso and Sheila Lukins.
Esther Oertel, the “Veggie Girl,” is a culinary coach and educator and is passionate about local produce. Oertel gives private cooking lessons. She welcomes your questions and comments; e-mail her at This email address is being protected from spambots. You need JavaScript enabled to view it..
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