Gourmet ballpark food is not the sort of cuisine that historically draws cultish crowds to the ArtCliff Diner. The Vineyard Haven eatery is better known to be abuzz in the morning with repeat patrons hankering for a warm stack of blueberry pancakes or a bacon-tomato-cheese frittata over potato wedges.

But if you have been to the ArtCliff lately, you must have noticed that a large white truck is one of the vehicles hogging one of the diner’s too-few parking spaces. If you pass by in the evening, long after the griddle has cooled, you will see the truck cocooned by its white glow, attracting strollers with hollow stomachs as a light draws moths.

It’s a mega-pushcart and the Vineyard’s newest oasis for cheap eats and midnight snacks. The truck opened two weekends ago for dinner and late night treats like hamburgers and lambburgers, spicy pork tacos, falafel, zesty mac and cheese, fresh strawberries and cream and berry cobbler. A notch above street vendor fare, the menu may not win the epicurean’s fancy, but it doesn’t have to. The kitchen-cart thing works because it serves quick, quality, no-frills fuel to grumbling tummies — fresh off the ferry or the bar stool — for $7 or less.

The truck is a mini 1950s diner spruced up with potted mums, a strand of multicolored string lights, a ketchup, mustard and relish-slathered figurine hot dog and a black and white photograph of a guy and gal sinking their teeth into burgers still dressed in plastic wrappers. Customers bend to pull an icy cola from a red bucket or bring their own six-packs to swig in parked cars or at a picnic table or a mismatched table and chair set. Waiting for their orders, served on trays or in handled paper bags, they snap and tap to Van Morrison and other soft rock tracks resounding from a speaker within the vehicle. On nice nights, the truck is teeming with customers who agree that there is something a bit romantic about grabbing a burger and a dance outside a contemporary food wagon at midnight. “It’s crazy busy,” says ArtCliff owner Regina Stanley. “It’s doing better than I thought.”

The truck is open Thursday through Sunday from 5 p.m. until any time between midnight and 2 a.m. Neither the menu nor the hours of operation are static, says Ms. Stanley, who caters her side venture to the tastes and drop-in trends of its customers. The mobile kitchen is available for home catering, but permit restrictions keep the vehicle parked outside the diner for all other events. Weather permitting, Ms. Stanley hopes to keep the rig running through late fall.