What were we thinking? We started our holiday shopping one Saturday in November at Potomac Mills Mall. Totally exhausted and $100 poorer, we wanted a lunch where we could relax, then resume shopping. We didn't care for burgers or any other fast food, and that narrowed the choices.

Several Extra readers had sent e-mails about a new restaurant. "The menu offerings are not run of the mill, and the prices are not unreasonable," Lee T. Koepping wrote. "It is refreshing to have something other than a 'chain' restaurant in the area."

Now we're spreading the best-kept secret in the Potomac Mills shopping area: Jazz Street Grill. By day it's a place for a classy lunch treat--grilled salmon on French bread or maybe a blackened tuna salad. Weekends, be transported to New Orleans courtesy of local jazz musicians such as the Dixie Power Trio, a group of twentysomethings specializing in Dixieland tunes.

Jazz Street is across the road from the Potomac Mills Mall, in the same spot where Carlos O'Kelly's was. The decor has changed--cranberry and cherry wood, Mardi Gras masks, prints and woodcuts of musical instruments, a piano--but the adobe walls of the former tenant can be seen among the dusty rose tablecloths and crystal goblets.

That's where the resemblance ends.

Think blackened red fish, crawfish cakes, chicken and andouille jambalaya. Head chef Greg Scott and sous-chef Jack Scott, his brother, are New Orleans natives. Greg Scott comes to Jazz Street from Jordan Hollow Farm in Luray, Va. His brother was lured north from a New Orleans restaurant.

In July co-owners Michael Lee and Bob DeMuth, Prince William residents, presented their dream recipe--Creole-Cajun food combined with jazz tunes. "We don't play," Lee said. "We just like that music."

"I don't know where we're going with the jazz," Lee said. "So far it's a mix of classic, contemporary and Dixieland." With little advertising, word has spread that there's a new place to hear jazz. Lee says he gets three to four inquiries a week from performers. "We're trying to support local musicians."

The Tim Ford and Easy Smith Duo have been regulars most Thursdays, playing from 7 to 11 p.m. Ford lives in Woodbridge, Smith in Manassas. They're scheduled to play Friday, and Dec. 2 and Dec. 23. Mark Trotta, band director at Lake Ridge Middle School, has performed solo and with his Mark Trotta Group. The Tony Matarrese Trio performs Dec. 17 and New Year's Eve. Also scheduled soon are the Signature Group and the Crawdads. Lee says special guests perform some Tuesdays and Wednesdays.

Ramon Ballve, pianist at the Prime Rib in Washington six nights a week, organized a recent Sunday evening jam session for local musicians.

"We're attracting an older crowd, over 30," Lee said, but "some younger people are coming for the jazz, too."

Filling the 240-seat restaurant has been easy on Thursdays and weekends. Lunches have been a little slower.

The menu at both lunch and dinner includes sandwiches (French dip, Reuben, classic BLT, shrimp and avocado), seafood gumbo, Cajun chicken pasta and lots of fresh fish: blackened yellowfin tuna, shrimp creole, crab cake remoulade, red snapper. No fish is ever revived from its frozen state; Lee says fresh fish is all the chefs will make.

We ordered dishes available at both meals. Crawfish ettoufe is billed as "the best thing on the menu." Two bites into it, we knew the chef was not idly boasting. The thick, dark tomato sauce crammed with crawfish was served on a bed of rice--a generous portion at lunch for $7.25 (at dinner, $13.50 with a salad, rolls, potato and vegetable.) "It's so good, I try to sell it to every table," our server, Beverly Hepburn, said. The dish was mildly spiced; we had expected more zip. "We've had to tone it down for some people," Hepburn revealed.

Salmon Toulouse ($8 at lunch, $16 at dinner) was a blackened filet topped with crab meat and tomato hollandaise sauce, diced scallions over all. The chef's signature garlic roasted mashed potatoes (we could have chosen french fries) were whipped to pillowy perfection. The red flecks of skin were tasty, the garlic subtle.

A basket of warm yeast rolls came with lunch. Unbidden, Hepburn refilled our glass mugs with coffee several times.

Coconut shrimp, battered and served with remoulade sauce, is so popular it can be ordered as an appetizer ($6), a Sunday brunch ($10.50 with fries, plus the pastry and fruit bar) or a full dinner ($15.75).

At dinner pan-seared mako shark with your choice of pesto or hollandaise sauce ($14) is a special once a week. Other specials include Veal Evangeline, sauteed veal in orange hollandaise sauce ($19) and Eggplant Piroque, deep-fried eggplant stuffed with crab meat and shrimp ($17.50).

Jazz Street's ambitious menu goes a step further than most: The chef says that if you don't see something on the menu that you're hungry for, just ask and if he has the ingredients, and he'll gladly make it for you. Co-owner Lee says they mean it.

Vegetarian dishes include Vegan Delight: roasted portobello mushrooms, roasted red peppers, potato lyonnaise and blanched asparagus, all wrapped in phyllo dough and served with honey roasted red onion and sugar snap peas. There's also cabbage rolls stuffed with rice, golden raisins and herbs.

Make a meal of the salad and fruit bar at lunch or dinner ($6.50 or $8.75, respectively). Besides the usual salad bar selections, there are trays laden with fresh melons, grapes and pineapple, grilled sweet red and green peppers and bowls of mammoth strawberries.

Sunday brunch includes sandwiches, salads with homemade dressings, entrees and traditional brunch foods with a twist: sweet potato pancakes with Grand Marnier syrup, banana and black walnut pancakes, wild mushroom and Swiss frittata, eggs Windsor with smoked salmon.

Desserts, all $4.95, are made in-house and change daily, but can include Bill Gates cake, a flourless chocolate cake with rum chocolate sauce, Kentucky bourbon pie and mango or raspberry cheesecake.

Banish the thought that this place is strictly for adults. Children 12 and under can order familiar foods--a burger, hot dog, chicken fingers or peanut butter and jelly sandwich, all served with fries, or spaghetti with meatballs--and color their personal place mat with crayons. Their meals include a drink and dessert. "There's even cotton candy ice cream," said Lee, who points out that his other restaurant, PopPop's in the Dumfries Shopping Center, is an old-fashioned ice cream parlor and deli.

Got a Prince William restaurant you'd like to spread the word about or a restaurant news nugget? Send e-mail to shumansk@washpost.com or kovachs@erols.com, or mail to: 9254 Center St., Manassas, Va. 20110

Jazz Street Grill

* Address: 14345 Potomac Mills Rd., Woodbridge; 703-497-8888.

* Hours: 11 a.m.-11 p.m. Monday-Thursday. Dinner daily 5-10 p.m.; 11 a.m.-1:30 a.m. Fridays and Saturday (after 10 p.m., sandwiches and light fare available); 10 a.m.-10 p.m. Sundays, with brunch 10 a.m.-2 p.m. Reservations are recommended on weekends.

* Credit cards: Accepts Visa, MasterCard, American Express, Discover, Diners.

* Prices: Lunch, $2-$8; sandwiches, $4.75-$8; at dinner, $3.25 soups, $6.75-$9 salads, entrees $11.50-$18.50 (some specials slightly higher). Sunday brunch, $7.25-$13. Our bill for two meals came to $21.55 with tip.

* Children's menu: $3.95, includes drinks and ice cream.

* Low-fat selections: Many choices, plus lots of fresh fish and vegetables.

* Health conscious: Try the bountiful salad and fruit bar or vegan platter.

* Atmosphere: Casual but classy.

* Downside: The restaurant is a bit hard to find in a shopping center across the street from Potomac Mills Mall. It's on the same lot at Staples and CompUSA.

* Upside: Plenty of free parking.