The first thing I noticed about Northside Social — well, aside from all the customers flocking to the new coffee shop/wine bar in Arlington— was the light. The two-story operation, housed in the former Murky Coffee space, is bathed in warm natural sunlight, as inviting as anything on the menu from the folks who also dish it out at the respected Liberty Tavern.

Sunlight, I’m beginning to suspect, has its own umami effect, brightening everything it touches, including the flavor of food.

Not that chef Liam LaCivita’s crisped pork belly sandwich needs any enhancement. The bite, a steal at $7, is like dense matter, a sandwich so concentrated in flavor your palate may not know where to turn.

The spiced pork belly comes served between slices of Italian feather loaf, which, as you can see from this crummy cell-phone snap, spent a little too much time around a heat source. I was somewhat alarmed by the burn marks, figuring it will have dried the bread out completely.

It hadn’t, thanks mostly to the generous amounts of moisture supplied on the interior of the sandwich. LaCivita slathers his creation with a heat-seeking salsa verde, smoked mozzarella, and, most brilliantly, a generous pour of Olio Santo, which acts as a sort of drill sargeant, bringing organization and structure to a sandwich that combines spice, bitterness (from broccoli rabe), richness, and smokiness.  I can’t wait to try the sandwich when the bread isn’t burnt.

We also ordered the chicken salad sandwich with pistachios, greens, and green goddess dressing, which was served on (if memory serves) oatmeal wheat bread. It delivered unexpected pleasures. Chicken was not the dominant flavor; the center of this sandwich was concentrated around these bright, creamy, and fresh green flavors, a balance of acid and herbs and dressing. The real surprise, for me, was how well this herbal garden paired with the oatmeal-studded bread. It’s as ticklish and unexpected as I imagine Mark Bittman’s oatmeal with celery is.

I need to add these two sandwiches to the working list. I also need to make a lot more visits to Northside Social, where sandwiches are just one of many apparent treats.