There’s a kind of genius at work behind the menu at Solbar, although Chef Brandon Sharp won’t take all the credit for it.

“It was our general manager who came up with the idea, I just fill in the blanks,” the chef at the restaurant at the newish Solage resort in Calistoga explained.

The idea is that the menu is divided, right down the middle. On one side is are “sol foods” — dishes on the lighter side “to nourish your soul” that are designed to appeal to guests in a spa kind of mood — dishes like spicy chicken lettuce wraps with glass noodles or an inventive salad of romaine and treviso with a goat cheese-olive dressing, amber grapes and mint.

But on the right are “hearty cuisine” comfort foods like sliders stacked with bacon, cheddar and 10-hour onions, red wine -marinated beef shortribs with thyme and garlic risotto, and pizza with Italian sausage and pickled Basque peppers.

It’s a kind of yin/yang menu, with satisfaction on both sides. It’s the kind of restaurant, for example, you can go to on a cold winter night, and if you’re feeling that perhaps during the holidays you ate enough rich food to sink the Queen Mary, you can order a salad of heirloom beets with cara cara oranges and a garnish of hazelnuts ($11) and a dish of lemon-steamed salmon with fennel and nicoise olives ($26) and feel wonderfully but righteously satisfied; whereas the teen-aged carnivore in your company can happily bask in the pleasures of barbecued pork buns with chile mustard sauce ($12) and flat iron steak with blue cheese potato croquettes, maitake mushrooms and beurre colbert ($29).

The Howard Backen-designed restaurant, described as “Napa barn meets San Francisco loft,” sets the stage for the friendly and accommodating yet sophisticated menu. The 125-seat restaurant features tabletops made from reclaimed Douglas fir, wool and leather upholstered lounge furniture, and low-VOC paint. It’s open and spacious with mountain views. At one end of the room is a bar with a television; but on a recent, rainy night the fireplace at the other end of the room and the candlelit tables created a cozy, intimate feel. Guests included a party of eight on what appeared to be a special night out, and a family with two small, extremely well-behaved children, along with quite a few couples.

“I was hoping that would be the case,” Sharp said. “In good weather, we can open up (the sliding glass doors) and people can sit outside to eat, but I’m glad to know this works well in the cold weather too.”

Sharp, who studied at the Culinary Institute of America in Hyde Park, N.Y., also earned his bachelor of arts from the University of North Carolina at Chapel Hill. His cooking credits include stints at the French Laundry, San Francisco’s Gary Danko and Restaurant August in New Orleans. Sharp draws inspiration from and designs his menu around the bounty of seasonal foods that surrounds him in northern Napa Valley.

The winter is more of a challenge, he said. “It’s when we all want those rich, comforting foods, but we’re sticking to this balance of lighter foods too.”

It’s not always so much what you’re cooking as how you’re doing it, Sharp noted in talking about his dichotomous menu. For instance, it was something of a surprise to see Rocky Junior Chicken and Dumplings on the light side, but, Sharp explained, he roasts the chicken to create a rich consommé that he uses in place of a velouté sauce, and uses a lighter pâte à choux, which because it puffs up looks substantial but is not as heavy as traditional dumplings.

The restaurant signaled its different approach even with the bread basket: It arrived with a combination of small, warm muffins and spaghetti-thin bread sticks. On a recent visit the seasonal menu offered such items on the “sol” (think, skinny) side as a winter squash velouté with granny smith apple and crispy sage ($12) and a tempting pasta dish of homemade ricotta and kale agnolotti that got a rich flavor boost from roasted cippolini onions, topped with tomato ragout and toasted pine nuts ($19). On that tempting “other” side was a handmade potato gnocchi with butternut squash brussels sprouts and hen-of-the-woods mushrooms ($12), seared sea scallops with Hama Hama oysters, salsify and house-cured pancetta ($28) and pan-roasted Durum pork chop with red cabbage, rosemary spaetzle and whole grain mustard ($25). Desserts, all $8, included an apple crumble with vanilla bean ice cream, walnut milk chocolate ice cream, a naval orange pot de crème with lemon shortbread, grapefruit sorbet and grapefruit crystals and a Medjool date and pistachio torte with espresso-banana ice cream and caramelized bananas.

The restaurant was also offering an amazing prix fixe menu, four courses designed to go with wines from Fisher Vineyards: a hickory-smoked salmon with russet potato rôsti and horse radish crème fraîche with a 2005 chardonnay; confit of Moulard duck with Beluga lentils, Nueske’s bacon and fuyu persimmon chutney with 2004 syrah, and egg papparadelle with shortrib ragout, black Tuscan kale and hen-of-the-woods with a 2005 cab. Dessert was a rich cup of hot chocolate with warm churros. Mid-winter splendor, for $35 a person; and an additional $25 for the optional wine pairings.

Because Solbar is beginning to number among their fans quite a few vintners, Sharp said, he hopes to offer more of these finely crafted wine-pairing menus. The wine list, by the way, is extensive as it should be and includes an impressive choice of Champagnes and sparkling wines.

Sharp shared his recipe and method for making the beet salad, which this writer requested after tasting it. And he also provided a sneak peek at the special menu he’ll be serving on Valentine’s day 2008:

Wild mushroom soup with Nueske’s bacon and black pepper croutons

Pan-seared striped bass with baby red beets, blood oranges and treviso

Olive oil poached duck breast and butternut squash risotto

And for dessert: Chocolate pot de crème with spearmint chantilly, milk chocolate ice cream, hazelnuts and a chocolate chocolate chunk cookie.

Talk about “sol” food.

The Valentine’s menu is $65 per person with a $35 optional wine pairing.

All in all, Solbar rates as a find, an inventive and extremely delicious addition to Upvalley restaurants.

Solbar is at 755 Silverado Trail. It’s open daily for breakfast, lunch and dinner. For more information or to make a reservation, call 866-942-7442.