Chef Brian Wilson lives by a motto: “Your mood is your food.” A hokey one, perhaps, but I can respect it. It’s a Like Water for Chocolate approach to cooking, in which a cook’s emotions season a recipe as much as salt and pepper. Spiga, a handsome three-month-old venture from Wilson and the Le Castagne crew — Wilson’s been the chef there for 11 years — should have his mental state running on a new-restaurant high, but the night I visited, his mood must have been very foul. Because the food certainly was.

Take the polenta fries, my first bite at Castagne’s casual little bro, self-styled as a place for “modern Italian dining.” I’ve never met ones I didn’t like, until I met Spiga’s. Stuck in a blob of garlic aioli as thick as cement, these limp, sad sticks had the color of wax and the constitution of Twizzlers. They ached for salt, as did their compatriots, a series of small, Italian-ish “assagi” snacks Spiga serves in groups of three for $15 and five for $20.

Dabbed with reduced balsamic, seasoned bread-crumb-crusted fried heirloom tomatoes and cool, wood-grilled zucchini roll-ups with lemon-and-thyme ricotta joined the fries on a long, dimpled plate, the least-violent offenders of the tapas. A crock of wood-roasted eggplant caponata, meanwhile, lacked both the campfire aroma suggested by its cooking method and the sweet-and-sour wallop suggested by its name. (I dare say Wilson’s nonna’s slowly stewed version, which inspired this dry one, is probably far better.) Stale crostini grew frostbitten in a bowl of chilly white-bean spread blasted with truffle paste and rosemary. It tasted like a truffled cleaning product.

Modern Italian dining? Maybe in 1999. Maybe in Marlton. But this is the big, bright city, and it’s 2012, and when Amis and Le Virtù and Barbuzzo and Modo Mio and Santucci’s and Osteria and so many others are all doing interesting, creative, artisanal things within the Italian tradition, how do you clear a place at the table for weak caponata and poorly seasoned polenta fries?

The friendly, pretense-free service makes Spiga’s strongest case. Our server, also the bartender, bounded like an earnest Labrador between the reclaimed Burlington County black-walnut bar and the flanking high-tops positioned within view of the latest Phillies shitshow. Cheery staff zipped between the window-encased dining room overlooking Locust Street and the back of the space, home to a pizza station equipped with a wood-burning oven and a kitchen that’s not so much open as it is doorless. You can see right in. I couldn’t get an eye on the salt cellar, but I imagined it to be filled to the top.

Salt might have made my pizza passable, even good, but without it, even ingredients as outgoing as sliced strawberries, balsamic onions and Robiola seemed muted, flabby and flat. The pie needed another minute in the oven, or a hotter oven in general, to blister the crust and provide a fuller wood-fired flavor.

The pizza may have been a passive-aggressive flop, but at least it didn’t launch a full-on attack against the taste buds. Can’t say the same for the crespelle, a pair of lumpy, bloated crepes so pale they appeared to be made of rice paper. A speedier take on his grandmother’s manicotti, the thin, open-ended triangles wept a runny lemon, thyme and white-wine sauce inelegantly creamed with mascarpone, an ill-advised flow sweeping up wisps of sauteed onion, chopped shrimp and cubed zucchini like wreckage in an angry flood. The garnish, julienned strips of tomato arranged in an X atop each crespella, was the unhip cherry on this ugly sundae.

Unfortunately, unbelievably, the pasta was not the worst thing I ate at Spiga. That dubious honor belongs to the coasters of cotechino arrayed over green lentils. Crowned with a fried egg, the composition echoed Modo Mio, while the texture of the sausage slices echoed Modo Alpo. Wilson poaches and chills the cotechino before slicing and searing, but that last step (which would provide some critical textural contrast) appeared to have been forgotten on my plate; the thick forcemeat rounds glowed virgin pink, no sign of caramelization anywhere. Remember the Play-Doh barbershop, how the “hair” would sprout from the holes in the character’s head? That’s what happened when I pressed my fork into the coarse-ground mush of the cotechino. It was like warm raw meat in the mouth, pasty and slick and rather revolting, but hey, at least the lentils underneath were really good.

Dessert brought a trio of deconstructed cannoli: smart vanilla, pistachio and chocolate ricotta layered between postage stamps of house-made shell. The tiny Napoleons shimmered with a fine dew, and the shells had lost their trademark snap, leading me to believe they were made ahead of time and refrigerated. (Wilson says no, they’re assembled to order.)

Redemption came on the back of the tiramisu cheesecake. Spiga’s version cuts a generous wedge fenced in by espresso-soaked ladyfingers, its coffee-spiked cream-cheese-and-mascarpone base dense, woven with ground espresso and not too sweet. It was the best thing I ate here, possibly even good enough to come back for. As for the rest of the food, I can’t say I’ll be rushing back. Mood is your food? Consider mine spoiled.

(adam.erace@citypaper.net) (@adamerace)

1305 Locust St., 267-273-1690, spigaphiladelphia.com. Open Mon.-Thurs., noon-10 p.m.; Fri., noon-11 p.m.; Sat., 5-11 p.m. Appetizers, $10-$15; entrees, $15-$26; pizzas, $12-$15; desserts, $6-$8.