Cut cheese into 1oz portions, or divide shredded cheese into 1oz portions
Using a box grater, grate your onion over a larger mixing bowl
Add the rest of the ingredients to the bowl and mix with hands until combined, the burgers should be wet, but if they feel too moist add a little more panko.
Place wax paper or parchment paper on a cookie sheet
Form 12 approximately 4oz balls with the burger mixture
Take one 4oz ball and flatten to a burger shape on the cookie sheet, with a dimple in the middle
Place the cheese in the dimple and take another 4oz ball and shape it over the cheese, working it around to create a burger patty that is completely sealed (you'll likely want to do this in your hands and then place it back on the cookie sheet)We had some mozzarella string cheese that we wound around the cheddar and that added a little extra gooey in the middle!
Once all six burgers are finished, place the cookie sheet in the fridge for 30 minutes, or 10 minutes in the freezer to firm them up before putting on the grill
Cook on the BBQ or in a cast iron pan to your desired temperature, they are large burgers with cheese in the center so they will take a little longer than you would expect
Top with your favorite burger condiments and enjoy!
Notes
If I can find a pork/beef mix or a meatloaf mix I often use that to add a little extra fat and some variation.Use a box grater to grate your onion and do it right over the bowl. You want all the juice.You can use any cheese you like, we actually had some mozzarella string cheese that we wound around some cheddar and they were amazing!These burgers freeze really well, place the paper lined cookie sheet in the freezer for a couple of hours and then place them in a Ziploc bag with paper between. Freezing them on a flat surface first makes them easier to pull apart later.