Smoked and seared wagyu picanha served over phở, with added vegetables (half a take-out serving shown here, prior to adding the usual garnishes)

There’s a sort of fundamentalism that exists in certain corners of the foodie universe, wherein self-appointed protectors of the cuisine will tell you which ingredients are allowed or not allowed in a dish. On the playful side, it might boil down to whether ketchup should go on a hot dog, or pineapple on a pizza. At the traditionalist end of the spectrum, someone might contend there can be no rice in a burrito, or insist beans don’t belong in chili.

Usually, arguments over purity surround cultural cuisines, likely with the insistence things only be done the way a person experienced within their community growing up. While it’s hard to argue against honoring traditions and preserving recipes, I do believe there’s a case to be made for deviations in the name of a great meal.

And this week, I think Shank & Bone has made this case, in a most excellent fashion.

Bear in mind, I’m on record criticizing the stylish Vietnamese restaurant in North Park for not making bánh mì as tasty or affordable as more traditional examples available a couple miles away in Little Saigon. Which, by the way, is still true.

At the same time, Shank & Bone’s selection of phở broths is among my favorite in the city, up to and including its vegetarian stock. The rich and memorably aromatic broths provide reliable comfort on cool winter evenings, which is exactly what I was after when I ordered take-out a few nights back.

Banh mi from Shank & Bone is tasty, but still not better than spots such as City Heights spots A Chou or Paris Bakery.

Which is when I noticed a special new offering in the menu: smoked wagyu picanha phở ($22).

This is a menu already loading noodles with options including brisket, short rib, oxtail, shrimp, crab, and bone marrow, and I wouldn’t have expected more. But, for a limited time, they say, they’re offering this smoked wagyu picanha.

Wagyu, of course, is a Japanese breed of cattle that yields beautifully marbled beef with fat that renders at lower temperatures. Which works wonderfully with this medium rare, smoked rendition of picanha.

That cut of beef is what we in the U.S. would call a top sirloin cap. However, different countries tend to butcher their meats differently. While our butchers tend to trim the fat from this cap, in Brazil, they cut picanha to feature a ribbon of fat, the way we more commonly do with brisket or ribeye.

Turns out, picanha fat nearly matches ribeye fat for flavor. Smoked and seared, and served atop Shank & Bone’s phở, these thinly sliced cuts of picanha come across as beef’s answer to pork belly, with the smokiness of bacon.

It’s not as authentic a phở add-on as, say, beef tendon, but it’s a terrific innovation I only hope a purist could appreciate. At any rate, I sincerely hope Shank & Bone decides to keep this special offering around awhile. It’s better than the rice in my burrito, and the beans in my chili.