EatBar's Hash Brown Burger may be a novelty, but it's even more delicious than it looks. (Fritz Hahn/The Washington Post)

Over the years, culinary thrillseekers have tried to shake up the humble burger by swapping the traditional breaded bun for more shock-inducing ingredients: pieces of fried chicken, seared discs of ramen, or even whole grilled cheese sandwiches.

The newest, and tastiest, variation in Washington is the Hash Brown Burger at EatBar on Barracks Row: layers of smoky pork belly, pickles and onions, covered with gooey melted cheese, and served between two crispy, well-seasoned hash brown “buns.”

Critics will note there's no beef patty, per se. And that's fine — it doesn't need one.

The Hash Brown Burger comes from the mind of Red Apron chef Nathan Anda, who also offers a pancake burger — a breakfast sausage patty, bacon, sunny-side-up egg and cheese between two pancakes — on EatBar's brunch menu. “Ever since I played around with the pancake burger, I've been trying to find new vehicles for burgers,” Anda says. “If you have the time to play around, you can figure out anything.”

The first iteration of the Hash Brown Burger was born at the Partisan, where Anda worked with sous chef Jeff Williams, who is now EatBar's kitchen manager. Hash browns were already on the menu, so it wasn't a leap to turn them into a bun.

The challenge, though, is to keep them from falling apart. Order the Hash Brown Burger, and you can see the crispy individual shards of grated potato that make up the bun. You start to worry that, after a bite or two, the bun is going to break apart or simply dissolve into pieces, as almost every ramen burger does.

But it doesn't.  “It has to stay together,” Anda says, because if you can't eat it with your hands, “it's a 'knife-and-fork' meal — which isn't a burger.”

Anda says the gluten-free hash browns, made of shredded potato bound by eggs, are cooked in circular molds on a flat-top grill until they're about three-quarters of the way done, and then tossed into a fryer to get them extra-crispy.

Why pork belly? There were enough beef burgers on the menu already. Topping it with egg or bacon was rejected because of the aforementioned pancake burger. “We wanted [the hash brown burger] to stay on the menu day or night, so we didn't want it to be associated with breakfast,” Anda explains. Rich, fatty pork belly, with a tangy cheddar and pickles to add brightness and acidity, paired well with the oily, just-out-of-the fryer hash browns, both in terms of flavor and texture.

After getting the thumbs-up from the staff, the Hash Brown Burger went on the menu in late summer, and Anda expects it to stick around for a while, or at least until he dreams up something else. “We've always played around with stuff,” he says, “so I don't know where we go from here.”

EatBar: 415 Eighth St. SE. Hash Brown Burger available after 4 p.m. daily. $13.