In the great burger discussion, the emphasis lately usually focuses on designer meat, whether it's from a famous butcher, a special grind technique, or an exotic added fat.

Kensington Quarters, which grinds its grass-fed, fat-forward beef daily from the whole cow that's cut up weekly at the in-house butcher shop, certainly has a special beef to tout, with a mineral richness that is beefy at its amplified best.

But what chef Damon Menapace also understands that many cooks don't is that a truly special burger requires great packaging, too.

So when KQ finally conceded recently to add a burger, both as a more affordable overture to its Fishtown neighbors and a signature move for its new lunch menu, he went about baking the ideal bun. This "pain au lait" (milk-based bread) offers the perfect middle place between soft and sturdy, with just enough squish to frame the great ingredients but none of the egginess I often find cloying with brioche.

And its delicate juice-containing crust is dusted with toasty sesame on top for good grip.

You're going to need it.

With an understated raw-milk cheddar, a tangy garlic aioli schmear, and a mop of onions glazed in vinegar-piqued molten tallow, this gorgeous fistful of a half-pound beauty has the umami punch to haunt my taste buds for an afternoon.

In a city already brimming with great burgers, the KQ has the knockout potential to contend as one of the best.

KQ burger, $14 (lunch)-$18 (dinner), Kensington Quarters, 1310 Frankford Ave.; 267-314-5086;