1 medium cauliflower, cut into florets
1 onion, very thickly sliced
Β½ small bunch flatleaf parsley, leaves picked and roughly chopped
Β½ tsp English mustard
40²µ/1Β½΄Η³ϊ plain flour
sea salt and freshly ground black pepper
ΒΌ tsp freshly grated nutmeg
40²µ/1Β½΄Η³ϊ butter
40²µ/1Β½΄Η³ϊ light mature cheddar, grated
600ml/1 pint semi-skimmed milk