This time of year, Portland's restaurants are just starting to slough their winter layers--the dreary demiglaces, root-vegetable purées, plates of thick-cut pork and sauce-smothered steak. But at clarklewis, the new restaurant from ripe's Michael Hebb and Naomi Pomeroy, it's already spring.

Light pours generously into the dining room through industrial-chic glass garage doors, so much light that it seems almost indecent for Portland in February. Blossom-studded branches stand bravely at the entry, while the open kitchen's butcher-block tables display a riot of torn greens, minced herbs, gleaming seafood and sliced lemons. The whole tableau festively defies Portland's darker moods--but then, the ripe crew has always been one step ahead. With clarklewis, which opened in January, their kitchen-tested method of ebullient experiment is writ large. And yes, it works beautifully.

Since 1999, when Hebb and Pomeroy founded ripe, their catering business, they've regularly displayed their fearlessness with food, outdoing themselves with experimental projects. There's the "Family Supper" prix fixe meals that began in their home, news of which spreads through a mailing list that now numbers in the thousands. There's the organic-modern Gotham Coffee Shop (2240 N Interstate Ave., 493-2646), which has brought light breakfasts and Italian caffeine to the transitional North Interstate corridor.

Now as the anchor tenant of lower Southeast's Eastbank Commerce Center--the building used to serve as the Grantree Furniture Warehouse--clarklewis offers more of ripe's trademark urban élan: industrial environs, rough-hewn furnishings, simple plating. Chic, yes, but it wouldn't count for much if chef Morgan Brownlow's food weren't really, really good.

On the dinner menu, each item is listed by its core ingredient--"mussels," "radishes," "lamb"--with preparations that flex and vary from day to day. The crisp endives that at one meal are dressed with anchovy, lemon and parmesan ($4-$8) are altered minutely at another, the anchovy cut now with the lemon swimming in a light cream. It's a finessed approach that celebrates and tinkers with a single flavor: When was the last time you saw so much attention lavished on a leaf? All of the greens--of which there are many, spanning from palest endive to cavolo nero, a black kale side dish ($3-$6)--taste so fresh that they justify the single-note strategy.

Some ingredients run like warp threads through the menu, binding the meal into a coherent fabric. You may find a kitchen favorite like artichokes marinated in a sandwich at lunch ($6), then flaked with dry parmesan and lemony olive oil in a dinner appetizer. Or fennel rough-chopped into a salad with blood oranges and oil-cured olives ($5), then stewed in a fragrant broth for a monkfish entree ($12). This creates a nice harmony across a meal, but can necessitate careful ordering--three similar dishes can mean three piles of parmesan, or simply more fennel than you bargained for.

The entrees offer a frank simplicity, allowing the meat to absorb the flavor of a few thoughtfully chosen ingredients. For example, the seared yellowfin tuna arrives smeared with mellow leaves of artichoke and slightly tart green olives ($12-$16), while the lamb shoulder stuffed with escarole and tomato ($12-$17) takes on the grassy taste of the vegetables without being overpowered.

The diner is invited to experiment as well. When my server informed me that the chef prefers to serve the squab with prunes ($14) "medium rare, but he'll go as far as medium," I put aside everything I've been told about raw poultry and simply trusted. The meat as served was spectacularly tender, kept that way by both the careful preparation and the sweet fruit that surrounded it on the plate.

Desserts, while traditional in concept, are distinguished by top-shelf ingredients and jewel-like accompaniments. Red-wine-soaked cherries rest atop the mascarpone semifreddo ($6), while candied kumquats cut the richness of the Scharffenberger chocolate torte ($6). Bold experimentation doesn't always produce perfect success--for example, the apple and balsamic crostata dessert ($6) was definitely astringent. But clarklewis' few sharp edges feel consistent with the restaurant's overall mission: acquaint the diner with the elemental tasks of preparation, lay bare the kitchen's secrets, try something new, try something new again.

The open-kitchen phenomenon isn't a new idea, but as you might expect, clarklewis' is more cinematic than most. The kitchen staff, identically dressed in orange T-shirts, move smoothly and quickly against a backdrop of glazed white tile and stainless steel, pulling mounds of arugula from tubs, rinsing mussels, scraping fennel bulbs across a mandoline.

When a lamb spezzotino ($12-$17) is mistakenly brought to my table, its return to the kitchen is dramatic. There's a brief conference between server and chef before the plate is handed off to the dishwashers. After surveying the dish mournfully, they slowly tip it into the trash (maybe they speared a forkful before tossing it, maybe they didn't).

The food at clarklewis is excellent, but the drama of moments like this are the crowning touch. A nicely prepared lamb shoulder might make a believer out of you, but that pride, the love clarklewis creators clearly feel for their own food, has a persuasive power--and a flavor--all its own.

1001 SE Water Ave., 235-2294.Coffee and pastries 7-11:30 am, lunch 11:30 am-3 pm; dinner 5:30-11 pm Monday-Saturday. Closed Sunday. Accepts checks and credit cards. $$ Moderate.

Picks: Definitely the lamb, however it's prepared; turnips as a side dish, roasted in duck fat; mascarpone semifreddo with red-wine-soaked cherries; Scharffenberger chocolate torte with candied kumquats.

Clarklewis' dinner menu offers an informal, mix-and-match approach, with starters and entrees available in small, large or family sizes to encourage sharing.

Ripe's Michael Hebb jokes that the new restaurant was launched as a way to keep chef and co-owner Morgan Brownlow from moving to San Francisco.

Why the typographically idiosyncratic name? "Because Michael likes everything in lowercase letters," says Sarah Serata, ripe general manager.