In a bowl add in the mince, salt and pepper and mix to break up the mince. Divide the mince into 2 even balls, using a chopping board flatten the mince balls into patties using the palm of your hand. Make the patties bigger than the bun as they will shrink in size once cooked.
Slice the burger buns in half horizontally and toast both sides under the grill. Once the buns are done, butter the inside of the buns and leave to the side.
Grease a large frypan with oil spray and heat it up on medium to high heat. Using a spatular carefully transfer the patties into the pan and add in the bacon and onion. Cook for 4 minutes and stir the onions and bacon regularly but cook the patties for 2 minutes on each side.
Place the cheese slices on top of the cooked side of the patties for a few seconds until slightly melted then remove it out of the pan along with the bacon and onions and transfer on to a plate and cover loosely with foil.
Scrape and clean away any charred bits stuck to the frypan. If needed spray more oil and heat up frypan on medium heat, add in the pineapple and eggs. Cook for one minute on each side.
Build the burger starting with the base of the bun. Add lettuce, tomato, beetroot, pineapple, beef patty, cheese, bacon, onion, sauce, egg and the top bun.