I'm sure this isn't something I've made up 
Is there a Jamie O recipe (possibly for lasagna) with a really quick and easy white sauce? Something like ricotta mixed with parmesan and an anchovy fillet? I can make Béchamel, even the quick MN microwave version but I want to try this for something different!
I can't find the bloody thing online though I probably could just look through all his books I CBA
Does anyone know what I'm talking about and is it any good?