How to make a great hamburger is a question that has bedeviled the nation for generations, for as long as Americans have had griddles and broilers, for as long as summertime shorts-wearing cooks have gone into the yard to grill.

But the answer is simple, according to many of those who make and sell the nation’s best hamburgers: Cook on heavy, cast-iron pans and griddles. Cook outside if you like, heating the pan over the fire of a grill, but never on the grill itself. The point is to allow rendering beef fat to gather around the patties as they cook, like a primitive high-heat confit.

“That is the best way to do it,” said George Motz, the documentary filmmaker who released “Hamburger America” in 2005 and has since become a leading authority on hamburgers. The beef fat collected in a hot skillet, Mr. Motz said, acts both as a cooking and a flavoring agent. “Grease is a condiment that is as natural as the beef itself,” he said. “A great burger should be like a baked potato, or sashimi. It should taste completely of itself.”

Michael Symon, the ebullient television Iron Chef, a host of ABC’s “The Chew” and a proprietor of a small chain of Midwestern hamburger restaurants called B Spot, agreed. Mr. Symon’s restaurants each serve more than 1,000 hamburgers a night, he said, all of them finished on a flat-top griddle coated in beef fat.