Kendall Square lunch cart shines in the sun

Eight years ago the Blue Room had a grand idea. While the new owners remodeled inside, they rolled out a mobile smoker and offered casual lunches on their pretty brick patio. Mainly it was a meet-and-greet deal to reintroduce the gourmet restaurant to its Kendall Square neighborhood.

The thing is, people liked it. The lure of expertly grilled meats and inspired sides loaded with fresh, colorful vegetables -- all for a spot price -- kept the techies from nearby offices and MIT returning for more. So the next year, owner/then-chef Steve Johnson and partners Nick Zappia and Deanna Briggs ) built a permanent grill outside. The lunch cart, as they call it, has made warm-weather lunches around here a joy ever since.

The setup is simple. For $6-$8, you get an entree and your choice of two sides. Just like the bistro fare served at night, the day menu changes to feature whatever's fresh. And unlike most lunches in this price range, every item is thoughtfully seasoned and, if called for, vibrantly sauced. If you've had the Blue Room's popular brunch, you may recognize some of the recipes. Without a doubt, the best dish is the grilled salmon with fennel vinaigrette ($8). The guys working the grill know to keep a high heat, so the salmon filets are as juicy as they come. Top this with the fresh flavor of shaved fennel, aromatic fennel seeds, and a vinaigrette buzzing with red pepper, and what was already great becomes perfect.

The salmon could pass for an upscale entree, but here everything is casual. You walk up to the grill to order, pick your sides, and it's all dished out lickety-split onto a plastic plate. You ladle the sauce yourself, grab some plastic cutlery, and find a seat. Iced tea and lemonade cost a buck, and you tap them yourself from big blue drink coolers. It feels somewhat like a community picnic, only at this "picnic" everybody can cook. The Monterey jack and avocado quesadilla ($6) was one of many hits. No frightening gob of rubbery cheese here: just a judiciously spread mash of creamy avocado and cheese with warming cumin, cooling parsley, and cilantro, all pressed inside a tender tortilla and grilled. With it comes a fresh, chunky salsa spiked with poblano peppers and lime -- a blend tasty enough to eat straight.

Grilled chicken breast is served daily. One day we had bland smoked tomato-basil chicken ($7) that was dry. The next we had perfectly moist mango chicken ($7) in a summery pineapple chutney, snappy with red onion and cilantro. Red meats, too, make the daily menu. Flank steak ($8) was plucked from the grill and sliced into thin strips to order. Though the cumin-rubbed meat was a tad tough (something less time on the grill could fix), it had superb flavor. Dry-rubbed St. Louis ribs ($8) were pre-wood-smoked on the inside grill to get a nice barbecue flavor and then finished outside over coals. The homemade barbecue sauce for the ribs was a riot of jazzy flavors -- Guinness, molasses, bourbon, and the house's version of recado rojo (here with chipotle peppers, lime, and garlic). The first time we had it, the whole shebang came un-pureed, but it worked, each flavor speaking up for itself, a sauce to remember. The next try, it was blended and too sweet. The third time, it was again a nice balance of tang and heat.

The inconsistency is part of the fun here, because things tend to go from good to great. Head chef Jorge Lopes and saucier/baker Sean Danehy oversee the lunch cart. But Danehy and the guys at the grill whip up many dishes freestyle once the day's ingredients come in.

"These are the same guys who put out the million-dollar menu at night, working all over the line whether it be the grill man or the saute man," says Danehy. Adds Lopes, "It's a fun way for them to have a little input and be experimental."

Pasta salads tended to be mild to a fault, but elsewhere the generally light touch worked. Pickled onion and a mildly tangy vinaigrette were all that a salad of sweet roasted beets needed. A toss of string beans with crunchy strips of red pepper had just enough sesame oil and soy sauce to bring out the garden flavors. Skin-on potato salad smartly relied on the fresh snap of celery and red onion and a thin dressing for big flavor.

Other sides reveled in the carbs, like corn-on-the-cob, jasmine rice, or chipotle pepper black beans; Atkins eaters can get a double of green salad. But for dessert, there's just one ideal choice. Every so often Danehy circles the patio to deliver a free slice of chilled watermelon to each guest. No wonder regulars keep asking why they don't stay open into winter.

Note: The cart shuts down on rainy days. No one answers the phone during the day, so you can't call ahead. Generally, if it's clear at 7 a.m., they open. Several adjacent eateries are open rain or shine, so you have backups.