Cheddar and Onion Quiche

semi-skimmed milk 40.0% , wheat flour 25.0% , egg 20.0% , onion 10.0% , mature cheddar 2.5% , extra mature cheddar 1.3% , palm oil 0.6% , red leicester 0.3% , medium fat soft cheese 0.2% , corn flour 0.1% , double cream 0.0% , corn flour 0.0% , rapeseed oil 0.0% , chives 0.0% , salt 0.0% , white pepper 0.0% , nutmeg 0.0%