In a medium pan, sautee the chopped onions in butter then add garlic. Remove once the garlic softens and set aside.
In a large mixing bowl, add the ground beef and all the ingredients listed and mix by hand until the mixture is smooth. Stop mixing once it looks even.
Divide the meat into 8 patties. Shape them just slightly bigger than buns as they shrink during cooking.
Set the patties on a baking sheet and use a spoon to press a dent in the center so they don't puff up as they cook. (at this point you can stack the patties for later use by separating them with a sheet of wax or parchment paper)
Preheat the skillet to medium heat (approximately 350-400 degrees F)
Cook to the desired doneness. 3-4 minutes per side for medium-rare, 4-5 minutes for medium, and 5-6 minutes for medium-well.
Add a slice of cheese to each patty and cook for an additional minute.
Toast the buns on the grill or in the oven.
Add the burgers to the buns then top with your favourite burger toppings. I added pickles, lettuce, tomatoes, mayo/sriracha and ketchup.
Serve and enjoy: Serve the burgers and enjoy while they are still hot and juicy.