good quality white sandwich loaf should do the trick. The cheese Jamie magazine recipe croque monsieur. Photograph: Felicity Cloake Gruyre is a firm, slightly elastic mountain cheese with a slightly sweet, nutty flavour. Most importantly for our purposes, it melts magnificently. Wikipedia France, however, claims that emmental is the more common choice (possibly, I speculate slightly cynically, because it's considerably cheaper). I substitute it in the Jamie magazine recipe, and decide I'm prepared to push the boat out for a decent croque: emmental's milder flavour is distinctly underwhelming. Julia Child, despite, one presumes, having consumed many a croque monsieur during her years in France, gives a recipe which calls for "mozzarella cheese or rather soft Swiss". Mozzarella, of course, dissolves like a dream when put in contact with heat, but, milky and unsalted, it lacks the distinctively cheesy flavour which the croque demands. Gruyre it is. The bechamel Waitrose recipe croque monsieur. Photograph: Felicity Cloake Of course, there is one thing that sets the croque apart from other great cheese and ham toasted sandwiches, namely that it sometimes (although not always) arrives at the table drowned in golden and bubbling bechamel sauce. Jamie magazine opts for a very simple, cheese-free version to top the croque, saving the Gruyre for the filling, while Saveur magazine not only uses it in the sauce as well as the filling, but sticks in some heretical parmesan for good measure. Although I find the plain bechamel a bit boring, I much prefer the sweeter Gruyre-only