Lasagne update

It's zucchini season again, so it's zuch lasagne time.  This year I've been making them with a cheese sauce, rather than using ricotta.  Not for any particular reason other than it's something I can make from ingredients in the cupboard and fridge, when there ain't no ricotta.  Also Harry knows how to make a cheese sauce and getting a six-year-old involved in the making of dinner is ALWAYS a good way to go.  So, without further ado, the cheese sauce, should you ever need to replace the ricotta from I ♥ ricotta, here it is...

2 tbsp butter
2 tbsp flour
1 cup milk
salt
pepper
good handful grated cheese (1/2 - 1 cup)
tbsp wholegrain mustard (optional)

1. Melt butter in saucepan.  When melted add flour and briskly stir in - this makes what is called a roux.  Add half of the milk, stirring constantly, so the mixture binds and is free of lumps. 
2. Add rest of milk, grind in some salt and pepper and mix thoroughly. 
3. Add cheese and mustard, stir through.  Continue to stir as sauce thickens. 
4. Turn off heat, sauce will continue to thicken.