Add everything (except cheese slices) into a large bowl.
Starting with a spoon, then use your hands, gently mix together until combined. Do not overmix, as the patties may become tough.
Divide evenly and shape the meat into 6 balls. Press and shape the balls until they form ½-inch thick patties.
Place patties on a baking tray (or plate) and refrigerate for 30 minutes to firm them up (and make them easier to cook).
Preheat barbecue to medium high heat (425˚F - 450°F). Cook for 5 minutes on the first side (lid closed), flip and cook for about 5-6 minutes more, or until fully cooked. Do not press, this will release the juices and they may become dry. If adding cheese, add during the last 2-3 minutes of cooking and close the lid to finish. Cook burgers to 160°F, and use an instant read thermometer for accuracy.
Remove cooked burgers from heat. If desired, grill buns on high heat for about one minute, and watch carefully until they are ready.
Prepare and serve with toppings such as sliced tomatoes, lettuce, sliced pickles, and your favorite condiments.
Notes
Nutrition is calculated without cheese slices.
To freeze patties:
place on a parchment lined cookie sheet, cover with plastic wrap and freeze for 6 hours or overnight.
remove from cookie sheet and place in a zip top bag for storage.
To cook from frozen:
cook for 5 minutes on the first side, flip and cook for 5 minutes more.
move to indirect heat for 10-15 minutes or until fully cooked.