Cut the bacon medallions into small pieces and finely dice the whole onion.
Mist a pan with some low calorie cooking spray, then cook the bacon and half of the onions until they are cooked through and lightly browned. Set aside to cool.
Meanwhile make up the burger mix (see instructions below).
When the onions and bacon are cooled, stir in the cheese and set aside.
Mix the minced beef, remaining onions, garlic, salt pepper, hot sauce and egg together until it's all combined thoroughly. Return to the cooked onion and bacon and stir in the cheese.
Split the burger mix into 4 equal balls, then put one ball into the burger press, replace the lid and press down firmly - you should now have a thin burger in the press. Make an indent in the middle of the burger, then add half of the cheese mix.
Take another ball of burger mix and flatten it slightly. Place it on top of the cheese mix, then replace the lid and press down firmly. Remove the burger from the press and repeat with the remaining burger mix and cheese filling.
Place in the fridge to firm up for 30 minutes.
Spray both sides of the burger with some low calorie cooking spray (so it doesn't stick to the grill bars) then place on the BBQ. Cook for 5 minutes, then turn and cook for another 5 minutes. Keep turning every 5 minutes, and check the internal temperature reaches 65 - 75°C (150 - 160°F).
Serve on your a roll of your choice. (We used 60g wholemeal roll).