Red onion and cheese beef burguers

beef 81.0% , red leicester 9.5% , red onion 3.0% , rice flour 1.5% , muscovado 0.7% , water 0.7% , cider vinegar 0.7% , cracked black pepper 0.7% , sea salt 0.3% , sugar 0.3% , salt 0.3% , dextrose 0.3% , bamboo fibre 0.3% , Preservative 0.3% , rapeseed oil 0.2% , corn flour 0.1% , Colour 0.0% , black pepper 0.0% , flavouring 0.0% , hydrogenated fat 0.0%