Each year, Americans consume about 38 billion hamburgers. An enduring favorite, hamburgers are an iconic American food.

But what do Americans define as the classic American hamburger?

According to the recent survey conducted by the Caravan Opinion Research Corporation for The Johnny Rockets Group restaurant chain, Americans still prefer the classics.

Despite the advent of gourmet hamburgers, 74 percent of Americans believe the cheeseburger best embodies the classic American hamburger.

Eighty-six percent of Americans also prefer beef hamburgers over turkey or veggie patties.

When it comes to toppings, most respondents agree simplicity is key, with 40 percent choosing raw onions over grilled.

What is the secret to cooking your own classic cheeseburger?

"From my personal experience, the best way to create that mouthwatering balance of beef and cheese is to grill the meat with the cheese on top," says Mike Shumsky, Johnny Rockets chairman and chief executive officer. "A true cheeseburger connoisseur will wait until the meat is fully cooked, then add a slice of cheese and cover for 30 seconds so that the cheese melts perfectly."

Here's a recipe for the restaurant's classic cheeseburger, the Rocket Single:

Rocket Single

Hamburger bun

Special sauce (mix Thousand Island dressing, Dijon mustard and hot sauce to taste)

1 slice of cheddar cheese

1/3 lb. fresh ground beef, seasoned, hand-pressed and grilled

Fresh lettuce

Ripe tomato

Onion (sliced)

Grill the hamburger, according to preference, until its internal temperature reaches 160o F. Place cheese on top and cover for another 30 seconds. Place in a bun. Mix dressing and spread it on the bun. Layer on tomato, lettuce and onion.

How do you make a hamburger a classic? Grill the meat with the cheese on the top, says one popular hamburger chain. Cover for 30 seconds to make the cheese melt perfectly.