As restaurants go more and more casual, one emerging common denominator is the burger. Can't keep up? No worries. We're tracking them at Burger Friday, our weekly blog examining all things patty and bun.

At the Rabbit Hole, chef/co-owner Thomas Kim's transformative approach to familiar staples starts — brilliantly — with burgers ($12 and $13, with fries).

In a kitchen that could write "The Joy of Fat," it's no surprise that Kim's inclination is to steer the patties as far away from lean as possible, fortifying a flavorful grind of brisket, eye round and chuck with short-rib fat.

From those 6-ounce building blocks, the menu offers four standards and a changes-frequently special. The most basic couples Cheddar with a heap of crunchy pickles, and it's divine.

But why not place yourself in Kim's more-than-capable hands and go on a texture and flavor joy ride? Of special note is the decadent Gruyère-blue cheese version, finished with kimchi-fired aioli, a fried egg and peppery arugula, although don't miss the version that utilizes a not-shy chile pepper relish, chipotle-infused coleslaw and what are possibly the city's most irresistible onion rings.

There's more good news. After nearly a year of a frustrating burgers-at-dinner-only policy, Kim is introducing them to his lunch menu next week. Sing hallelujah. Naturally, Kim counts himself a huge burger fan.

"The first restaurant that I owned was a small burger stand in Redondo Beach [California], so burgers have always been near and dear to my heart," he said. "It's the quintessential American food."

920 E. Lake St. (Midtown Global Market), 612-236-4526, www.eatdrinkrabbit.com. Lunch and dinner, Monday-Saturday.

Doubling up in Uptown

At Lake & Irving, brothers Chris and Andrew Ikeda took no chances on their path to burger nirvana.

"The burger is what so many people screw up," said Andrew. "We want to make it as perfect as possible, every time."

And they do. Their burger ($11, with fries; for a crisscross of expertly fried bacon — highly recommended — add $2) starts with a steakhouse-style short rib-chuck blend, imported from New Jersey's Pat LaFrieda Meat Purveyors and a grind so flavorful that it barely needs salt and pepper. Although the end result very nearly comes off as a single patty, each burger doubles up a pair of 3-ounce-ers. Picture it this way: rather than a clearly delineated double patty, imagine a thickish single patty, albeit one with a slightly off-kilter shape.

Here's the fascinating part: Each patty is cooked on a 500-degree flat-top grill for a precise — as in, down to the second — amount of time, a figure determined by a ton of trial and error. While immersed in their R&D period, the brothers stumbled onto an "aha" moment: During that quick grilling period, each patty benefits from a hard press with a spatula, a la Smashburger.

"It's counterintuitive, I know," said Andrew. "At the CIA [Culinary Institute of America], we were taught that if you ever take the back of a spatula to a patty, the patty will lose moisture. But on a hard flat-top, it doesn't. It's the fattiness in the short rib, which locks all that flavor and moisture into the patty."

The two-patty formula is genius, in part because the thin shape requires next to no cooking time before each center reaches a picture-perfect pink. These burgers very nearly fly out of the kitchen, making L&I a smart lunch destination for the time-pressed.

Another integral element is a Wisconsin-made Cheddar. The sense of restraint continues with the burger's other garnishes, a few marvelously made pickle chips, a modest sliver of red onions and a lettuce leaf, all served on the side.

Then there's the crowning touch, a brioche bun from Patisserie 46, a golden, flaky, buttery thing of beauty that has quickly become the bun by which all others are measured. At L&I, it's lovingly split and grilled in butter, caramelizing until it reaches the color of dark butterscotch.

"A lot of the credit goes to Patisserie 46, because that bun is dynamite," said Andrew. Agreed.

Not convinced? Consider the numbers. The Lake and Irving cheeseburger is outsold only by the kitchen's category-killing fried chicken sandwich. The latter has developed a (well-deserved) cult following. The burger merits similar standing.

1513 W. Lake St., Mpls., 612-354-2453, www.lakeandirving.com. Lunch Monday through Friday, dinner daily, brunch Saturday and Sunday.

Richfield revelation

After logging nearly six years in the kitchen at Restaurant Alma, chef Benjamin Rients has set out on his own. At the center of his menu at Lyn 65 Kitchen & Bar is an item that's far outside Rients' Alma orbit: a burger. Scratch that. A phenomenal burger ($13, fries included).

"I want to set us apart from Alma," he said. "I want this to be a neighborhood place, and a burger is important to a neighborhood place. Besides, I absolutely love cheeseburgers. We're approaching it the way you would at a fine-dining restaurant. Why not take some craft and put that into a burger?"

The unseen, elaborate mechanics are suitably impressive. The patty owes its voluptuousness to fat-laced short ribs, cured for 48 hours and then blended with chuck and sirloin — the arithmetic is roughly 50 percent short ribs, 25 percent chuck and 25 percent sirloin — before being hand-formed into patties and grilled on a flat-top.

"That way, the patty sits in its own fat and caramelizes," said Rients. "It's using the fat that's already there."

When the patty comes off the grill, it gets a brief respite in, yes, more fat. Butter, specifically.

"It's the way we were taught at Alma, to rest our proteins," said Rients. "If you have that fat underneath, it acts as a natural barrier, and the patty might not release as much of its juices."

Naturally, a fine-dining level of care and feeding goes into the garnishes. The top of the lower bun gets a generous swipe of coarse mustard. That's covered with a layer of dill pickles, which serves as a protective barrier between doughy bun and juice-laden patty.

A second pickle treatment — this time, a sweet pickle relish blended with chopped raw onions — is spooned over the patty. Rounding out the equation is an obviously well-raised tomato, a crinkled lettuce leaf and a well-composed house-made mayonnaise. As with all classic formulas, this one works. And how.

From the get-go, Rients planned to call upon American cheese.

"I love American on a cheeseburger," he said. "It's what belongs on a cheeseburger. It melts the best, it's salty, and it's perfect in a hipster-ish kind of way, you know? The 'Ah, who cares, let's put American on this thing.' "

From a profit-and-loss standpoint, is a humble cheeseburger worth all of this effort?

"I'm going to say 'Yes,' " said Rients. "At least until I can't stand it any longer."

6439 Lyndale Av. S., Richfield, 612-353-5501, www.lyn65.com. Dinner daily.

Prowess on Payne Avenue

When chef/co-owner Leonard Anderson opened Tongue in Cheek in late June, the plan was to always include a burger on the menu. "We want to accommodate more than one demographic," he said. "If there are two people at a table of six who aren't that adventurous, they can get a fried-egg sandwich, or a salad, or a burger. We're selling a lot more burgers than I ever thought we would."

No wonder. Turns out that the formula is a kind-of happy medium between two burgers from Anderson's recent professional past: the fully loaded iteration he created for the former Hanger Room, and the minimalist version from his days at W.A. Frost & Co.

At its center is a lean and flavorful grass-fed beef that Anderson fortifies with shallots, garlic, herbs (dill, rosemary, thyme, parsley and chives) and a bit of ketchup. The meatloaf-inspired mix is formed into a thick patty and grilled to a robust char. On the outside, anyway; the kitchen took my medium-rare request exactly where it needed to go, leaving appropriately velvety pinkness and plenty of juice.

Anderson keeps the fuss to a minimum. The bun, a basic beauty baked by the good people at Franklin Street Bakery, gets its blackened stripes from a quick burnish on the grill. In the cheese department, Anderson uses a mild, three-month-old Cheddar (from Castle Rock Organic Farms in Osseo, Wis.) because it boasts all the right soft, meltable qualities. From the garden, Anderson skips over more standard-issue lettuces in favor of arugula.

"It's my favorite green, along with watercress," he said. "I like it because it has a little more of a bite, and the texture holds up."

The finishing flourishes? House-made pickles, and whatever aioli is being prepared in the kitchen that day.

"Tonight it's a chipotle aioli," Anderson said. "Last night it was Sriracha. Sometimes it's roasted garlic. I have the burger a lot. I want to change it up, so I assume that others want that, too."

The price is right, too: $11 (with fries), a top-notch value. "There are places that are charging $14, $15, $16, $17 for a cheeseburger, it's crazy," said Anderson.

989 Payne Av., St. Paul, 651-888-6148, www.tongueincheek.biz. Dinner Tuesday through Sunday, brunch Saturday and Sunday.

Loring Park's latest

What a pleasure to find chef Lucas Almendinger at the helm of the Third Bird, the Loring Park newcomer that opened in late August in the former (and more enchanting than ever) home of Cafe Maude at Loring (and, before that, Nick and Eddie). The Tilia vet is a huge talent; witness the impact he made at the short-lived Union Fish Market, a notable new-in-2013 endeavor.

For the burger on his lunch, dinner and brunch menus ($11, with chips), Almendinger is skipping beef in favor of grass-fed bison.

"Bison is a little healthier than beef, and it's unique," he said. "I'm from South Dakota, and I sort of love bison. There are bison burgers all over South Dakota, and they're not good, so I wanted to do a good one."

Mission accomplished. Almendinger wisely exercises restraint, allowing the meat's gentle, pristine flavor to speak for itself. The only (well-calibrated) seasoning is salt and pepper, and then the thick, hand-formed patties are fried on a flat-top in butter, a welcome fat injection for the naturally lean meat. Composition-wise, Almendinger is offering a tribute of sorts to fast-food burgers, and the muted, scrupulously attended-to details bear that out.

A Thousand Island-style dressing serves as a shout-out to the Big Mac, but Almendinger's far more flavorful aioli-based version isn't exactly Mayor McCheese territory, what with its Sriracha (for subtle heat) and cornichons (for brief acidic flashes) touches.

White onions are sliced thin and coaxed on the stove to sweet, near-black caramelization, then finished with a splash of mustard oil. A stack of pale, crisp iceberg adds just-right crunch.

As for the bun, it's a soft, milk-laced beauty, its golden top studded with sesame seeds and its interior toasted on the grill. They're baked on site, and they're terrific. As for the Wisconsin white Cheddar, Almendinger chose it because it boasts all the right melty qualities, and it hails from owner Kim Bartmann's home state.

"The focus of what I want to do here is be a Midwestern restaurant," he said.

1612 Harmon Place, Mpls., 612-767-9495, www.thethirdbirdmpls.com. Lunch Monday through Friday, dinner daily, brunch Saturday and Sunday.

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