Season the meat with kosher salt and fresh ground pepper. Shape patties that are 3/4-inch thick, using 3 ounces for sliders and 6 to 9 ounces for classic burgers.

In the interest of food safety, keep your hands clean, handle the meat as little as possible, and keep the patties refrigerated until it's time to cook. The commonly advised practice of letting meat sit at room temperature for 15 or more minutes before cooking does not apply to ground meat.

Also, don't serve or carry cooked meat on the same plate that held it when it was raw.

Flay's final precooking tip: Make a deep depression in the center of each burger with your thumb. This prevents the burger from puffing up and bulging in the center. A burger that's bulging on the grill tempts cooks toward the worst possible burger infraction: patty smashing.

Never do this - never press down on the burger with a spatula while it is cooking. That just diminishes the juiciness you're working so hard to attain.

You won't see the thumb depression on the finished burger because it disappears as the meat cooks and expands.

If you can't cook outside, remember that good burgers also come from stove-top griddles and cast-iron pans.

For medium-rare stove-top burgers, Keller heats a tablespoon or two of olive oil in a large cast iron pan over medium heat until very hot. For sliders, cook about three minutes total, turning once or twice. (For full-size burgers, cook until brown on the first side, about one minute. Turn and brown on the second side, about three minutes. Turn the patties again and baste several times with the pan juices while cooking for another three minutes.)

On the grill: Build a medium-hot fire in the grill, brush the grate to clean it well and, once it's hot, oil it well. Place the burgers over direct heat. Cover the grill and cook for about 11/2 minutes on each side for sliders. (For full-size burgers, brown on the first side for about 11/2 minutes; give the burgers a quarter turn, re-cover the grill, and cook for another 1 1/2 minutes. Then turn the burgers over and repeat the process on the second side. About 7 minutes of cooking time should yield a medium-rare burger.)

Let burgers rest for a couple of minutes before cutting or biting into them. This allows the meat to continue to cook very gently while the juices seep throughout the meat.

Flay favors cheeseburgers above all others and says the cheese must melt properly and ooze down the side of the bun to create the proper juicy mess that defines a classic.

To attain that perfection, Flay uses a basting cover, an inexpensive aluminum dome that resembles the lid of a saute pan, except that it is domed to fit over the burger. A basting cover allows just enough clearance so the cheese doesn't touch and stick to it.

If you don't own such a dome (they're favorites with short-order cooks) improvise with a sturdy metal bowl, or close the grill cover, or tent each burger with a square of aluminum foil.

Philadelphia Slider Burgers

Makes 4 servings or 8 sliders

3 1/2 tablespoons canola oil, divided

1 large Spanish onion, sliced into thin rings

1 1/2 pounds ground chuck (80 percent lean) or ground turkey (90 percent lean)

Kosher salt and freshly ground black pepper

8 slices aged provolone cheese, each 1/4 inch thick