In most every language, “sandwich” is a synonym for delicious. Case in point, Las Primas, a new Peruvian joint on North Williams Avenue next to the Box Social, which ditches ceviche for street-food offerings punched up with creamy South American sauces. Not everything at this eatery works, but Lima-born cook Catalina Acuña’s juicy sandwiches, from thin-sliced pork to spicy chorizo, are great.

The best one I’ve tasted so far is the pollo a la brasa ($8.50). The kitchen roasts chickens marinated in beer, soy sauce and “Peruvian spices” and gives them a quick smoky sear on the grill just before stuffing big hunks of the moist bird into crunchy, pillowy, football-shaped loaves that Fleur De Lis Bakery makes special for the restaurant. There’s also a bunch of iceberg lettuce, tomato and a creamy, spicy sauce made with Peruvian red rocoto peppers. All the sandwiches are served in plastic baskets, nestled next to big piles of very thin, very tasty fries or a citrus-spritzed salad. You could not ask for a simpler, more satisfying lunch. That is, unless your tablemate orders the perfectly seared lomo saltado steak sandwich ($8.50), piled high with fat grilled onions and doused in garlic sauce, so you can go halvsies on both. 

There’s also a handful of less successful housemade empanadas ($3.50)—the spicy chicken is good, the bland, dry mushroom is not—topped with the traditional funky sprinkle of powdered sugar as well as a trio of uninspiring salads ($6-$8), chicken wings ($5) and yuca fritters ($5). And that’s about it, aside from a lineup of beers and sweet Pisco and rum cocktails.

That abbreviated menu makes Las Primas, Spanish for “the cousins” and a nod to Acuña and her cousin/co-owner Sadie Morrison, a bit odd. The sunny yellow, light-filled space is huge, with long, family-style tables, two- and four-tops, a foosball table and an Incan coin-toss game called sapo—all below a festive mural of ponies and birds that the cousins painted. It looks ready to host an entire fútbol team and its fans for a postgame celebration, complete with servers carrying huge platters of food and bottles of that piss-colored, bubble gum-flavored Peruvian obsession Inca Kola ($2) to the table. 

Although those wonderful sandwiches are good for a quick takeout lunch, Las Primas needs to offer more variety of dishes, from seafood to a chicken entree, as well as table service in order to lure a sit-down dinner crowd. Right now, the outsized space is a ghost town at most hours. You order at the counter, and the nice server gives you a free taste of shocking purple corn juice ($2) while you debate if you should get a churro from the hot case ($1, yes you should). Then you sit and quietly chew in time to the pan-flute tune on the sound system. 

I’m rooting for this place to turn into a bigger Peruvian party in the future.

• Order this: Pollo a la brasa, papas fritas with cheesy salsa huancaina, puckery passion fruit juice.
• Best deal: Lomo saltado sandwich with fries ($8.50).
• I’ll pass: Dry mushroom empanada and super-saccharine Pisco Punch cocktail. 

EAT: Las Primas Peruvian Kitchen, 3971 N Williams Ave., 206-5790, lasprimaskitchen.com. 11 am-9 pm Tuesday-Sunday. $.