If you know about the Red Hook Tavern burger — a hit in Brooklyn, the stuff of cheeseburger legend — you’re in luck; a sister restaurant has opened Sag Harbor Tavern, and yes, that burger is on the menu. “Everything I do is in homage to something else. This one is for my grandma,” chef Billy Durney said of the new spot, which is located in the American Legion hall near the marina.

His grandmother served in World War II and recalls a childhood in East Flatbush surrounded by veterans. “I grew up in and around the American Legion halls of Brooklyn, and that meant so much to me,” he said. The Sag Harbor space is as clubby and warm as the Red Hook location, with deep blue leather banquettes, the same floral wallpaper as Red Hook and a wooden corner bar.

It features more seafood than Brooklyn, with a nod to local fluke, steamers and three varieties of North Fork oysters. “We added a couple more pastas and we just finished recipe for local spicy fluke crudo,” Durney said. There’s a squid ink tagliatelle ($30), mussels, fish and chips ($28), a branzino ($50) as well as a second steak — a hangar with chimichurri.

Plus that wonderful house cheeseburger ($30), which Durney said is “identical” to Red Hook's, down to the same people grinding the meat and baking the buns. The Sag Harbor Tavern at the American Legion Hall has a patio with outdoor seating. Credit: Newsday/Marie Elena Martinez Sag Harbor Tavern will be open year-round, with 42 seats inside and 70 on .