RESTAURANT REVIEW : Classic Bistro Hits Most, but Misses Some : Appetizers are the most consistently enjoyable dishes at comfortable Keller’s in Ojai. But pastas can be puzzling.

Roger Keller’s Restaurant proudly and discreetly occupies a former storefront just north of the arcade in Ojai’s downtown. You’ve seen this kind of place before, whether it be in Litchfield, Conn., or Portland, Ore.: exposed brick walls, spare table arrangements, well-lighted photographs or paintings by regional artists. The ethos within very clearly emphasizes comfort and taste without pretension.

The menu, of course, reaches for perfect symmetry: something knowing, classic, rooted in rich traditions yet with a modern, audacious spin--but always without fuss, without the Limoges, without self-consciousness.

Keller’s usually succeeds in carrying out this multifaceted mission. And it is more difficult to achieve than the casual look of things would suggest.

Service must be unobtrusive but gracious and responsive. It is. The setting must be consistently pleasing and comfortable. It is again. And the food must be smartly conceived and executed. Often it is, but sometimes, sadly, it is not.

Poached salmon ($15.45) on one night will be slightly dry, overdone. On another, however, this king filet will be quickly finished beneath the broiler with Dijon-watercress butter and served with perfect potatoes and fresh green vegetables.

On one night, a dish described as Sicilian spaghetti ($6.95), in which noodles are tossed with chopped tomato, basil, onion and garlic, is gutless and bland, defying the mandate of its origins.

Yet on another night a rather eclectic American conception--rock shrimp and bay scallops in linguine with pesto and sun-dried tomatoes ($13.95)--astonishes in the depth of flavor and perfect doneness of its tender shellfish. (In all pasta cases, however, noodles are al dente, that is, never overdone, and while this may be a no-brainer for a kitchen to achieve, it is no small accomplishment in these parts).

Appetizers turn out to be the most consistently successful dishes. Spicy eggplant Parmesan ($5.95) is fresh, firm, vivid in its flavor and accented with sparkling tomato-and-basil combination. Bruschetta ($5.45), a rustic rendering on thick grilled bread, is every bit as successful and more than enough for two people. An appetizer of salmon spinach ravioli ($6.25) is lustrous and decadent in its rich filling, enhanced by a bright tomato and basil accompaniment.

Caesar salad ($6.50 or half for $3.25) is, for once, the real thing. It is traditionally prepared, free of all cream or subverting goops, and throws a forceful garlic-and-anchovy punch. (A worthy consideration would be a large Caesar with one of the excellent appetizers.)

Pastas, as noted, court risk. Something called black and white angel hair ($8.95), which incorporates tomatoes, roasted garlic, basil, Kalamata olives, and grilled tofu, is a thick undifferentiated mass--and bland to boot.

Braised chicken ($13.45), with mushrooms, pearl onions, carrots and celery in red wine sauce, is deeply flavorful but dry from overcooking. But roasted pork medallions ($14.45) are sponge-tender and brightly sauced in whole-grain and Dijon mustards, accompanied by sprightly apple compote.

Filet of beef au poivre ($16.95), in which the tenderloin is encrusted in cracked peppercorns and flashed with brandy, is just right: medium rare, as ordered, and deep enough in flavor to withstand the pepper’s onslaught.

Keller’s functions as a respectable dessert bakery as well, and on this count I would recommend not missing the lemon pound cake. It is simple, dense and sharply flavored. Since my palate is chocolate-dumb, I left those judgments to chocoholic dining companions; all raved about the various dark cakes offered.

The menu is complemented by a small, well-selected wine card, with moderate prices. Some varietals are offered by the glass, but be sure to ask how long the bottle in question has been open; uncorked wines here are not stored in a Cruvinet, and on one visit a Merlot was well on its way to being pavement-flat.

It’s obvious that talent abides in the Keller kitchen. With some effort at weeding out those few dishes that don’t work or retuning them so that flavors are distinct and robust, the food would match the space and feeling and fulfill its trusty and by now almost-delivered promise: Ojai’s old reliable bistro.

Details

* WHAT: Roger Keller’s Restaurant.

* WHERE: 331 E. Ojai Ave., Ojai.

* WHEN: Lunch from 11 a.m. to 2:30 p.m. Monday through Friday, till 3:30 on Saturdays and Sundays; dinner from 5 to 10 nightly (note: till 9:30 p.m. midweek during winter months).

* HOW MUCH: Dinner for two, food only, from $20 to $60.

* CALL: 646-7266.