The burger: All right, burger lovers, if you haven't availed yourself of the spectacular specimen being served at Constantine, then the only logical conclusion is that you currently reside beneath a rock. That I've spent the last several months curled up under a gigantic slab of Minnesota-mined granite is the only plausible explanation for not yet raving about this burger.

Nostalgia is a powerful force, because a hefty part of this burger's appeal is the way it skillfully touches – correction, reaches out and bear hugs – the happy memory that many of us have with the single-patty McDonald's cheeseburger of our youth.

That's certainly the case with chef Mike DeCamp (pictured above in a Star Tribune file photo, in the dining room at Monello, located upstairs from Constantine). "I just liked how you could eat a bunch of them," he said. "It's such a good memory of when I was a kid."

Fun fact: DeCamp, like many other top-tier chefs, got his start at McDonald's. Well, near-start, anyway; his first restaurant job was washing dishes at a pizzeria in Madison Lake, Minn., when he was 14, "and that's still my favorite pizza," he said. But within a year he was wearing the uniform at a McDonald's outlet in Wayzata. He even moved into the management trainee program before deciding that it wasn't for him. Still, "I learned a lot about organization," he said, along with a first-hand lesson in the hard work that goes into a restaurant career.

His most lasting takeaway was an abiding affection for that basic-as-can-be burger, and all the components that go into it: thin patty, white onions, pickle chips and a specific, semi-elusive style of bun.

"The bun is everything," said DeCamp, which explains why he and his crew laboriously taste-tested a number of models, in search of the just the right one. They found it at a bakery, labeled "kid's bun."

For what DeCamp is going for, it's perfect, at least by the time the wrapped-in-paper burger arrives at the table. That's because both the insides of both the top and bottom halves of buns are treated to a prodigious swipe of butter (Minnesota's own Hope Creamery butter) and a lingering toast on the flattop. The result? The bun's browned insides exude that wonderfully modest crinkle that comes from butter-slathered, warm-from-the-toaster toast, while the rest of the barely warmed bun remains soft, even slightly squishy.

"That's what I like about it," said DeCamp. "It's the kind of bun that can absorb a lot of butter, and also absorb a lot of fat from the burger. When it's cold, you can almost crumble it apart, but once it's warm, it gets soft and really holds together."

The patty is unlike anything ever served at McDonald's, where "hot" is pretty much the only valued characteristic. By contrast, the Constantine burger's patty is a near-parody of flavor and richness.

"It's just chuck and brisket, there's no fancy rib eye in there," said DeCamp. "And we don't work it too much. It's a loose burger, it's kind of spongy."

The beef is formed by hand into balls, and smashed into the flattop grill with a spatula until it's very thin, its thickness measuring somewhere in the 1/4-inch range.

Size-wise, think slider; this is not one of those situations where the patty and bun achieve a kind of real estate parity. Peel back the bun, and the cheese, and you'll discover a fairly diminuitive patty. Not that it matters, because, small as it is, this is a patty that possesses a bigger-than-life flavor.

The secret ingredient? Butter. Scandalous amounts of Hope Creamery butter. "For every six parts meat, there's four parts butter," said DeCamp, and although we were talking over the phone, I could almost see him smiling, maniacally, at the prospect of such divine culinary overkill. "We'll grind a 40-lb. case of butter into 60 pounds of beef."

Yeah, that's a lot of butter. It doesn't end there. The patties are cooked in butter, too. The finished product may look fairly modest, but appearances are deceiving. This burger packs a dietary wallop.

"You can't eat too many of them, because they're so rich," said DeCamp.

Clearly. I ordered two, and shortly after I'd inhaled the first one, my circulatory system was ready to cry "uncle." In a good way.

As for the condiments, DeCamp maintains a strict adherence to McDonald's protocol. Well, mostly. The cheese is a slice of white American, a switch-up from the chain's caution sign-tinted American. "It seems a little fancier than the yellow cheese," said DeCamp, noting that it's also a healthier choice: refraining from the yellow dye means one less processed ingredient. Because eating this burger is such a health-conscious choice. Sure.

Anyway, it's delicious, and the straight-up white onions and vinegar-ey pickles insert a bracing (and welcome) contrast to all that fat.

The pickles' back story is a good one. After trying to fashion his own version of a fast-food pickle, DeCamp threw in the towel. In the name of authenticity, he's now using a commercially prepared variety. "It's almost impossible to recreate a food service pickle," he said.

"Melt in your mouth" is one of the most over-used expressions in the food-writing lexicon, but it applies to this burger, and how. Rely upon a single bite, and the conclusion is clear: the chef who spent most of his career in the hallowed halls of La Belle Vie has more than proven that he is capable of making a top-rated burger.

"We're not trying to start a burger joint," said DeCamp. "But this style of burger is a memory that we all have. I hate to give McDonald's so much credit, but they're definitely the inspiration for this burger. I guess they did something right."

Price: $5. Sure, it's not a monster of a burger -- more like, a half-dozen bites and you're out -- but five bucks represents a significant value.

Fries: None. Instead, Tater Tots (on the menu, DeCamp dubs them "Tater Barrels"), a heaping basket ($7) served with a rotating selection of cheese sauces. When I dropped in, it was Manchego (and fabulous); other recent versions have been aged Cheddar and brie.

I asked DeCamp what it is about Tots. "Fries made in-house are inconsistent," he said. "So that leaves using a frozen product. But if you're going to buy a frozen product, get Tots."

Why? "The crisp ratio is higher," he said. He's right. And that crispiness is addictive. It took every shred of what remains of my self-control to scarfing one after the next after the next, like so much deep-fried candy. DeCamp buys the bite-size variety – they're really more corks than barrels – and takes them to a deeply crispy (but not crunchy) place in the fryer, pulling them out when they reach a deep golden, almost caramel color, the delicately crispy exteriors collapsing into piping hot, potato-ey insides. They're proof positive that somewhere along the way, the human body was programmed to crave hot, crispy, salty, processed potatoes.

I asked DeCamp if he ever thought of making Tots on the premises. It's the trashy cousin of a croquette, so how hard can it be, right? Wrong. His response was basically, are you kidding? "We've got about 40 Tots per order, which means it would probably take three or four days to make a single order," he said with a laugh. "Sometimes we just have to give in to Better Living Through Science."

Two notes: First, don't leave without ordering Constantine's sole dessert, a skillfully prepared, smile-generating homage to the Pop Tart ($3). Kellogg's has never come within a hundred miles of this crust's delicate flakiness, and the tasty, ever-changing fillings (lingonberry, s'more) are far too good for the supermarket shelf.

Second, someday, when a group of pals want to throw $250 to wind, we're going to head to Constantine and order DeCamp's gleefully headlong dive into indulgence: a whole foie gras lobe. Served with pancakes. Yeah, I love this place.

I'm no Scavullo: Don't judge the photos too harshly. Basement-level Constantine is dark. Like, safely-process-a-few-rolls-of-Kodak dark. My sole source of illumination was a candle. Romantic, yes, but not exactly conducive to snapping images on an iPhone.

Address book: Constantine, 1115 2nd Av. S., Mpls., 612-886-1297. Food available 5 p.m. to midnight daily; bar open to 1 a.m. Sunday through Thursday and to 2 a.m. Friday and Saturday.

Talk to me: Do you have a favorite burger? Share the details at rick.nelson@startribune.com.