Crack the egg into a large bowl
Pour in the diced onion
Add the mince
Combine thoroughly with your hands until all of the egg and onion are mixed into the mince
Grab your preference of burger size mixture, roll into a ball, and press with a burger press on grease-proof paper. If you don't have a burger press, sandwich the meat orb between grease-proof paper and flatten with something flat.
Repeat for your desired number of burgers
Into a grilling pan, put a dash of cooking oil and place on medium heat
Place the burgers into the pan once heated up
Wiggle the burgers occasionally to ensure they don't stick to parts of the pan where the oil wasn't
Every few minutes, turn the burgers over to ensure they are evenly cooked
Once fully cooked, remove from pan and serve