The tuna steak frites at the new Cornerstone in Somerville. (Photo: Tom Meek)

Fans of those big, fat charcoal-grilled burgers accompanied by ginormous onion rings at R.F. O’Sullivan & Son on the line dividing Cambridge and Somerville: Sorry, the 30-year feast is over. After several changes in ownership and revivals before and during Covid, the bar and burger joint on Beacon Street finally came to a close. You can still stroll in and score a burger, but at the newly opened Cornerstone it will be something else: a half-pound wagyu patty.

Yup, the new shop takes its cues from Japanese and Hawaiian cuisine. It’s still essentially a gastro-pub – and these folks are top-chef-skilled with the Frialator – just with far-flung accents of fare we don’t generally see in these parts. The New England, Hawaiian and Japanese fusion comes from cultural traditions as well as family roots. Dad was a cook at Faneuil Hall back in the day and is the inspiration for a Summahville Clam Chowdah, as the menu tells us, while chef David Toraji Oshima has spent time in Hawaii and worked at the lines-around-the-block Japanese noodle destinations Yume Ga Arukara and Yume Wo Katare.

The menu is not vast, but it is varied and has a lot of “I need to try that the next time I come in” offerings. Working through that list – and the menu has shifted a few times since a soft opening this month – I can say on the appetizer side, the Hawaiian chicken salad is a surprising gem with crisp, light greens, shredded dark-meat chicken that feels and tastes slightly like a confit and a semi-sweet dressing that has island flavors of sesame and pineapple. To say it has the effervescence of a Chinese duck sauce would be fair. The lanakila nui (“big winner,” if I have that right) on the appetizer list is the succulent shrimp (I feel I been writing about shrimp a lot lately) sautéed gloriously in a rich garlic butter and white wine sauce with red pepper flakes. It comes with a warm, lightly grilled wedge of airy bread to sop up all that good sauce, reminding me some of the head-on shrimp dish at Gufo. Also on the apps slate are fried clam strips, tuna ceviche and, to keep it pubby, Tennessee chicken wings and carnitas tacos.

On the mains, fried is where you want to be – and this is coming from one who tends to shy from fried foods. Not here, where the fish and chips uses fresh mahi-mahi, lightly fried tempura style to be tender and moist. Its tartar sauce felt like more of an aioli; I wondered if not a ginger soy or classic tartare sauce might have complemented the delicate and flaky fish better. The key here is the french fries, skinless sticks also done in that tempura style that have no trace of greasiness and remain warm throughout the meal, so you don’t need to jump on them first. These are, without question, the best fries I have had in my recent, recallable culinary past. 

Moco loco, Hawaiian comfort food at The Cornerstone. (Photo: Tom Meek)

The tuna steak frites is another surprising hit, like the mahi-mahi lightly fried but coming out sushi-rare in the middle and cutting like butter. There’s a medley of a sweet soy ginger, wasabi aioli and a spicier red sauce to dip into. Tuna trois couleurs – or ʻekolu kala, to be more on point. As advertised, it comes with those fries. Also interesting is the veggie tower of grilled eggplant, zucchini, onion and more done with a balsamic glaze and dressed in a butternut crème with potato quarters (whatever those are, steak fries?) on the side. The note on the menu says the chef felt bad for vegetarians growing up and said, “no more!”

The bit of Hawaiian street food on the menu is the moco loco, a lean beef patty atop a mound of moist rice with gravy – a hearty homestyle eat. Think of it as Salisbury steak comfort, island style. 

If I had two druthers about Cornerstone, it would be to lose the slippery and too-easy-to-tip barstools from Sullivan’s – when you walk in, not much has changed – and to dim the lights some. (Though the bright lights do make taking food snaps easier.) That said, Cornerstone is a great addition serving up belly-warming fare with touches from around town and afar, and let me restate: Those perfect fries are worth a trip in their own right.   

The Cornerstone, 282 Beacon St., Spring Hill, Somerville

Tom Meek is a writer living in Cambridge. His reviews, essays, short stories and articles have appeared in the WBUR ARTery, The Boston Phoenix, The Boston Globe, The Rumpus, The Charleston City Paper and SLAB literary journal. Tom is also a member of the Boston Society of Film Critics and rides his bike everywhere.