I rarely ate out as a little girl, so it was always a special treat to stop at Friendly’s with my mom for the occasional tuna melt and milkshake, typically a pause during a busy afternoon of errands.

Cera, a newish sandwich shop in Portland’s Monument Square, reminded me of that, maybe because I ordered a “tuna-ish” sandwich, which always evokes nostalgia for me, or because I sat near the large windows overlooking the square on a February afternoon as the bright sun streamed in, enjoying both my sandwich and a rare, quiet pause from work’s never-ending deadlines.

The sandwich itself ($13) – with its lively flavors, precise pickle dice, alfalfa sprouts and wood-grilled cobia fish – was quite an upgrade from Friendly’s. The menu helpfully let me know that cobia “eats similar to swordfish and is sustainable.”

Similar notes, “good for you, good for the planet,” pepper the menu and the storefront itself. The recycling station, for instance, is carefully set up to show diners exactly what they may compost, recycle or throw out; getting this wrong is the bane of many fast-casual restaurants and compost pickup services. Local ingredients (Morse’s sauerkraut, Pineland Farms steak) are touted. And by the counter, Cera, which means “honeycomb” in Latin, sells Maine honey, $8 for a 10-ounce jar. “All profits of this honey go to saving the bees,” notes a handmade sign with a doodle of a bee. (It’s worth looking at the website; the place wears its heart on its sleeve.)

The Black Pearl at Cera is made tuna-salad style but with more sustainable cobia fish. It’s shown here on multigrain bread.

At Friendly’s, I probably had potato chips with my tuna melt. At Cera, I ate a healthier and tastier Freekah Salad (a steal at $3). It was nice to see this tasty, underused grain on the menu, and I also appreciated the julienne of likewise underused jicama in the salad. The salad was a study in contrasts: crunchy carrots; chewy freekah; crisp jicama; soft, sweet raisins; and a bit of heat and bite from the scallions and nice, fresh arugula. (About that last, am I the only one who has been disappointed by mesclun mix salads at fast-casual chains in which some of the greens are beginning to rot?)

Cera’s Freekah Salad is both healthy and tasty. Photo by Peggy Grodinsky

Cera offers an array of sandwiches, wraps, paninis, salads and sides. I was tempted by the Portobello schnitzel (fried mushroom cutlet) with pickled beets, greens and miso mayonnaise ($11.50) and the pork tenderloin with tzatziki on naan ($12). Next time.

One complaint, and not an insignificant one given that sandwiches are the focus here: the bread. I tried the multigrain, which was a little stale and tasted like an upscale supermarket loaf. It’s made by FireKing Baking, out of Massachusetts; not to malign our neighbors, but given the many wonderful bakeries in Maine that sell bread wholesale, I think Cera can do better.

The restaurant – exposed industrial ceilings, modern pendant light fixtures and lots of Scandinavian-esque light wood – is very clean, and the staff is very friendly, calling out cheerful goodbyes to customers as they leave. You order at the counter – the open kitchen is just behind it – and a staff member brings out your lunch. Midafternoon on a Thursday, I had my food in less than five minutes. You can sit at booths, window counters or tables, or you can take your meal home. I did both.

The tuna-ish sandwich – Cera calls it the Black Pearl – was hefty. The Freekah salad was generous, too. I could only manage half of each for lunch, then wrapped up the remains to bring home. On the usual busy work day, I ate the remainder for dinner. Which was a treat.