Flay recommends purchasing meat from shops that grind it fresh daily. Stay away from pre-packaged or preformed patties, which Flay says can be inconsistent in freshness, texture and flavor.
Bruce Aidells, author of "The Complete Meat Cookbook," agrees that ground chuck is the way to go but says that for the ultimate burger you can grind your own at home using a food processor.
He suggests purchasing boneless chuck with the outer fat (called the fat cap) attached. Chuck meat often is sold with most of the fat trimmed, so you may need to ask your butcher to do a custom cut or sell you some extra fat.
Aidells recommends making sure the beef is very cold before grinding it. He even suggests chilling the food processor blade for 30 minutes in the freezer before starting.
Cut the meat and fat into 3/4-inch chunks and grind in small batches using the pulse function. Combine the batches and gently mix. Using this cut of beef and grinding in this manner should produce a ground beef that is roughly 80 percent lean.
When it comes to shaping the burger, both Aidells and Flay call for a fairly flat, uniform patty no more than 3/4-inch thick. Try not to overwork the meat or pack the patty too tight, or your burgers may come out tough or dry.
Flay takes the extra step of making a deep thumbprint in the center of each burger. This helps keep the burger from swelling into a football-like shape while cooking.
For seasoning, Flay sprinkles the outside with kosher salt and ground black pepper, sometimes a spice rub, too. But he never mixes into the meat any spices, condiments, onions, garlic or fillers such as breadcrumbs. Do that, and you've got meatloaf, he says.
