Ground beef.

Cheese (pramesan)

Egg

Onion

Pepper

take a bowl, add the beef add the egg and mix with your hands. take some cheese and mix it in.

Forming the patties:

Form the patties into meatballs. then squash it down with your palm. Remember to take out any air that's left inside the patties. (having air in the patties causes it to break the pattie while cooking) Make sure there aren't any tears in the pattie.

Fire up the grill. Put the patties on and add some onion if you want. Salt and pepper to tase. I like adding chili spice to it. Grill and enjoy.

What I do sometimes is take 1 patty and a piece of mozzarella cheese and put it in the middle. Then take another pattie and cover the first pattie with it. So I get 1 burger with cheese in the middle.