“I’m not a big filet mignon fan,” Todd Hatoff said as he showed me his company’s operation. That was somewhat surprising, since his company is Allen Brothers, the century-old Chicago meat wholesaler. Then he added, “But you know, if I’m not feeling well, like if I have the flu, and I want a piece of meat but can’t handle too much flavor, then I’ll have a filet, because it’s very mild.”

That tells you everything you need to know about Mr. Hatoff: He thinks steak is a flu remedy.

Mr. Hatoff is a fourth-generation meat man. He’s Allen Brothers’s president, which means he sets the standards and specifications for some of America’s best beef – beef that you’ve probably eaten at some point. If you’ve ever had a steak at Morton’s on East 45th Street, or at any other Morton’s location, you’ve eaten Allen Brothers meat. Same goes for Del Frisco’s on Sixth Avenue, and for many Smith & Wollensky outlets (although not the one in Manhattan), along with loads of other top steakhouses nationwide. The rise of these steakhouse chains over the past 10 to 15 years has fueled the growth of Allen Brothers, which is now America’s top purveyor of USDA Prime-grade beef.

I wanted to get a better idea of how the steaks at these restaurants (and from Allen Brothers’ excellent mail-order operation, available at www.allenbrothers.com) go from the hoof to the plate, so to speak, so I arranged to stop in at the company’s offices during a recent trip to Chicago.

If you’re expecting a tale of abattoirs and carcasses, forget it. Although Allen Brothers is located out in the city’s once-bustling stockyards area, no livestock has been slaughtered in Chicago in nearly two decades. “The Jungle” is no more. That work is now done near the feedlots where the steers are fattened up, primarily in the rural Great Plains. After slaughter, the steer carcasses are broken down into what are called primal cuts: the loin, round, chuck, and rib. These sections are graded by federal inspectors – the ones with the highest degree of fat marbling are graded Prime – and are then sealed in Cryovac bags, packed in boxes, and shipped to purveyors like Allen Brothers.

Allen Brothers has contracts with the major packers to ensure that the company receives an abundant supply of Prime beef. “But even if we didn’t have contracts – in other words, if we were spot-buying – the packers need to move this product,” Mr. Hatoff said. “And because of all our restaurant customers, we can move it for them.”

When the beef arrives at Allen Brothers, most of it is either dry- or wet-aged, depending on customer specifications. (A few restaurants prefer to do their own aging, so their beef is shipped to them immediately.) Wet-aged beef is left in its Cryovac bag for several weeks, which tenderizes the meat as its connective tissues break down, while the dry-aged meat is removed from the bag and placed in a low-temperature, high-humidity aging room for at least three weeks, where much of its moisture evaporates, concentrating its beefy flavor. Today’s beef has to be aged longer than yesteryear’s because advances in slaughterhouse sanitation have actually made the meat too clean when it leaves the packer – just as with cheese, you need some bacteria growth to get that good aged taste.

Most steak purists, myself included, agree that wet-aging increases tenderness but does little for flavor, although Mr. Hatoff tried to finesse the issue. “It’s like different kinds of chocolate – one’s not necessarily better than the other,” he said. “With a wet-aged steak, the fat is so sweet, and it fills your mouth, while dry-aging produces that rustic beef flavor.”

That’s a tactful answer, but when we compared wet- and dry-aged steaks during a luncheon tasting, it was no contest – the dry-aged beef had a fuller, more robust flavor. So why do some restaurants and butchers use wet-aging? Because dry aging is much more expensive. The evaporation robs the meat of 10% to 14% of its weight while it sits in the aging room, so there’s literally less product at the end of the process than at the beginning. In addition, the exterior edges of dry aged meat develop a dark, moldy crust that has to be cut away and discarded, leaving even less salable product.

Downstairs at Allen Brothers’s refrigerated cutting room, where dozens of unionized cutters don jackets and wield knives, I watched as an employee cut a craggy-looking dry-aged loin into gorgeous strip steaks. “That outer crust, we call that the scab,” Bobby Herrera, the plant’s operations director, said. “We take off an inch, at least, to get to the nice red meat inside. Some customers prefer to receive it with the scab still on, so they know it’s been dry-aged, and they cut if off themselves.”

However the meat is aged, it’s cut into steaks according to customer specs (each cutter has his own digital scale, to ensure that what’s listed on a menu as, say, a 26-ounce rib-eye weighs out properly) and then shipped. But most of the steaks for Allen Brothers’s mail-order operation – which are aged six to eight weeks, a mix of wet and dry, depending on the cut – are flash frozen first.

“If I left you in here for 45 minutes, you’d be frozen solid,” Mr. Hatoff said as he led me into the company’s freezer, where the temperature dips below zero. “When you freeze something that quickly, there’s no chance for any of the blood to get out. That’s why, if it’s done properly, you can’t tell the difference between a frozen steak and a fresh one.” He was right – I’ve done that taste test myself in the past – but my teeth were chattering too much for me to voice my assent.

Back upstairs in the warm office, I asked Mr. Hatoff to elaborate on his feelings about filet mignon. After all, it’s many people’s favorite cut. “It’s a tender steak, but it drives me a little nuts when people get all excited over it,” he said. “Really, a filet is a filet is a filet. The real test of a meat man is how well he can do all the other cuts.”

Fortunately, Allen Brothers has enough ribeyes, sirloin strips, T-bones, and porterhouses to pass that test. And if you need to get over the flu, they’ve got filet mignon, too.