|Hamburger buns||4 (4 Inches In Diameter)|
|Extra lean ground beef||9 Ounce (1 Cup, Such As Round And Sirloin)|
|Vegetable oil||1⁄2 Teaspoon|
|Onion slices||4 Medium (1/4 Inch Thick)|
|Shredded sharp cheddar cheese||2 Ounce (1/2 Cup)|
|Dill pickle slices||8 Small (Thin Ones)|
1. Preheat a broiler or toaster oven for toasting the buns and melting the cheese. Toast the buns.
2. Place four 6-inch squares of waxed paper on a flat surface. Scoop 1/4 cup of the ground beef onto each and pat into 4 very thin 4-inch patties. Leave the patties on the paper and use your fingertip to poke a small hole in the center of each one to minimize shrinkage during cooking.
3. Place a large nonstick or well-seasoned skillet over moderately high heat. Lightly coat with the oil. Plop in the burgers, aiming for the right spot because you won't be able to reposition them once they hit the skillet. Peel off and discard the waxed paper. Drop in the onion slices around the burgers and cook for about 2 minutes, until the burgers are browned. Turn with a spatula and cook 1 minute longer, or to taste. The onion slices will take a little longer than the burgers; cook just to soften, 3 to 5 minutes.
4. Place each burger on the bottom half of a toasted bun. Sprinkle each with 2 tablespoons of the cheese. Run under the broiler just until melted, about 1 minute. Spread the bun tops with 1 teaspoon ketchup and 1 teaspoon mayonnaise. Add the sauteed onions and 2 dill pickle slices to each, place over the burgers and serve hot.