Cookbook:Beef Burgers with Onion

These burgers are filled with onion and topped with melted cheese.

Ingredients

 * Vegetable oil
 * Onion, chopped
 * Ground beef
 * Egg
 * Sliced cheese
 * Lettuce
 * Tomato, sliced thin
 * Ketchup

Equipment

 * Frying pan
 * Bowl
 * Knife
 * Grill

Procedure

 * 1) Heat a thin layer of vegetable oil in a frying pan. Add the onion, and fry for about 5 minutes until softened. Remove from the heat and cool.
 * 2) Combine the ground beef, egg, and cooked onion.
 * 3) Shape the beef mixture into patties. Cook the burgers on a grill for about 6 minutes, flipping halfway until browned on each side and cooked through.
 * 4) In the last minute of cooking, lay a slice of cheese on top of each patty. Cover and let the cheese melt slightly.
 * 5) Lightly toast the hamburger buns. Sandwich the patties in the buns, topping with lettuce, tomato, and ketchup as desired.