Constantine Stavropoulos is known for his laid-back food concepts, and that’s just fine by the creator of the popular Diner and Tryst in Adams Morgan.

“We want to be that third place,” after home and work, says the restaurateur, who also claims a Tryst in the Phillips Collection, Open City in Woodley Park and the Coupe in Columbia Heights.

The last concept, rolled out in October, is a ’round-the-clock hybrid coffee shop/watering hole/restaurant beneath a pressed-tin ceiling that will look familiar to customers of his older establishments. Big, open and fragrant with the aroma of coffee, the Coupe fills one side of its long, glass-wrapped storefront with faux-leather banquettes and a coffee bar and the other end with comfy sofas and a bar dispensing even stronger fuel. Attention, book clubbers: One round table seats 10, “twelve if you’re good friends,” jokes Stavropoulos. Chalkboards originally hung to promote the menu instead invite guests to think beyond their appetites. “What makes you smile?” a staff member scrawled across the black canvas on a recent visit.

I would answer with “eggs any time of the day,” an option at the Coupe, where their many guises include a respectable omelet with shallots, Swiss cheese and spinach.

Another dish that elicits a grin is the lamb burger, a patty that goes Greek with feta and gets extra kick from sun-dried tomato mayonnaise and pickled red onion.

As for the Caesar salad laced with white anchovies: well, not bad for a diner.

Venture into more adventurous territory and a chowhound risks disappointment. Sriracha-glazed chicken wings sound topical and tropical, but their heat is faint and the accompanying carrot slaw amounts to rabbit food. Salmon finished with harissa and bedded on cubed sweet potatoes and spinach is a muddle of unexpectedly shy flavors. The kitchen can be careless; roasted Brussels sprouts should not crunch in the mouth. The cocktails are good, but not so polished as to remind you that the city is one of the country’s best for drinking.

The servers, when they materialize, are mostly helpful (and diligent about making sure that if you’re fewer than a trio of customers at peak hours, you don’t occupy a prized window booth).

A reason for night owls to whoop: the Coupe’s hours. Off the top of my head, I can’t think of anywhere else in town that serves vegan French toast 24/7.

3415 11th St. NW. Sandwiches, $8.99 to $11.99; entrees, $12.99 to $19.99.