Heat the oven to gas mark 5/190 degrees C.
Prepare your sprouts by washing, trimming and cutting them into quarters.
In a large pan, bring a large amount of water to the boil and add your quartered sprouts. Once the water comes back up to the boil, let the sprouts boil for two minutes, then remove from the heat and drain.
Melt the butter in a small pan, and then add the flour and milk, continually beating to create a smooth and lump free paste. Warning – this bit can get very very spitty so wear an apron and keep at arms length! If, once you’ve added the milk and the sauce is still very thick, keep adding a little bit of milk at a time until it’s smooth.
Once you’ve got a nice consistency, lower the heat and add the grated cheese, the two spoons of mustard, and your salt and pepper (to taste). Give it a good stir to mix it all in.
Add the sauce to your sprouts, stirring well so that the sprouts and sauce are well combined.
Spoon into an ovenproof dish and spread it out so that it is evenly distributed.
Mix your grated cheese(s) and breadcrumbs in a separate bowl.
Cover the sprouts evenly with your grated cheese(s) and breadcrumb mix.
Place in the oven for 20 minutes, until golden brown.
Serve and enjoy, and never pass on the sprouts again!