Driving around the Boston area, I’ve always been perplexed as I pass by all the eateries advertising roast beef, because of both the sheer number and my lack of understanding about what goes on inside.

Are they serving it as a cold cut, in a French dip, in slices like at a holiday dinner?

I had no idea and had never been quite curious enough to stop and find out, until this regional version of roast beef rolled into Maine.

George’s North Shore was one of three roast beef food trucks that showed up in Portland around the same time last year, along with Roll Call and Halstead’s. Although it appeared to me some trend had suddenly reached our corner of the world, it was mostly a coincidence.

Each truck serves a different style of roast beef sandwich from different parts of the country. Roll Call pulls inspiration from beef on weck, popular in western New York, and Halstead’s does Chicago-style Italian beef sandwiches.

But George’s could finally offer me a taste of what was happening behind the doors of those roadside eateries in the Boston suburbs. Parked by Battery Steele Brewing on Industrial Way on a Saturday this fall, it was well positioned for me to finally give it a try.

George’s offers its signature – and only – sandwich, the Classic North Shore Beef, in super and junior sizes ($14/$10), served “three-way,” meaning with cheese, barbecue sauce and mayonnaise. You can opt to “murder it” with extra sauce for 50 cents or add other toppings (“if you must,” the menu reads) that include lettuce, pickles and onion for free, as well as horseradish for 50 cents and onion rings (aka “a four-way”) for $1.

Sides include fries ($5 small/$8 large/$10 three-way), onion rings ($8) and, in the straightforward menu’s one curiosity, broccoli bites ($8).

Thinking the junior size was for kids, I got the super (it’s actually more like lunch versus dinner), with pickles, and a side of fries to share with my lunch date, whose Husker Du T-shirt elicited admiration from the cooks working in the back of the truck (“We like band shirts here,” they explained). The fun, friendly service made that always-awkward situation of choosing a tip amount upfront much easier.

I spent the 10 minutes it took to make the order grabbing a beer and a seat outside Battery Steele. Had I known better, I would have spent part of my wait on that windy day developing some sort of napkin strategy, in which I could always have a clean one easily accessible without it blowing away. Because when I unwrapped that sandwich – a sloppy, saucy bundle of super soft beef in a squishy onion roll – it was clear I wasn’t getting out clean.

The addictive flavor of all the melding toppings on the melt-in your-mouth meat made it difficult not to try to devour, but the monstrous size and hand-smothering sauce made it impossible to do so without taking breaks to wipe down.

The fries were unique in both seasoning and style, somewhere between standard and steak, and overflowed from their paper boat into the bottom of the takeout bag. I thought maybe my tip got me a few extra, but judging by the freewheeling spirit that emanates from George’s – embodied by its namesake chihuahua/pug – it’s more likely just how they do it.

The whole experience had me questioning Mainers’ hardline stance on our neighbors to the south. And if this is an accurate representation of what’s served in those mom-and-pop shops, after George’s shuts off its engine for the season in a few weeks, I might even pay them a visit.

This story was updated at 9:08 a.m. Tuesday to remove information about Roll Call’s West End shop, which has closed.