Yesterday’s Croissants with Mustard, Gruyère & Lemon

In my house, these are just as likely to be the Sunday morning croissants begging to be used up fast for a late Sunday tea after a long lunch. They make a welcome change for the usual boiled or scrambled egg brigade and will even cheer the children up on what is usually the gloomiest night of the week. It is always worth having grainy mustard and some sort of good meltable cheese in the fridge.