Preheat the oven to 190°C/ 170°C fan/ gas mark 5/ 375°F
Grease a 1.5 litre gratin dish
Mix the milk and evaporated milk, to a total of 500ml. Heat in a microwave or saucepan to below boiling point
Make the breadcrumbs if necessary
Grate the cheese
Put aside about 30g cheese for the topping and mix with the breadcrumbs
Chop the ham into 1-2 cm squares
Heat a large pan of water to cook the macaroni
For the Cheese Sauce:
Melt the butter in a large saucepan over a medium heat. Add the flour and cook for 1-2 minutes
Add about a quarter of the milk and stir well as it all starts to bubble. Once you have a solid mixture, add the next quarter of the milk and repeat until all the milk is used upIf it’s lumpy, use a stick blender or silisone whisk to smooth it out
Add the mustard and nutmeg. Add 300g grated cheese, stirring, and taste as you add salt
When the cheese has melted and the sauce is smooth, take off the heat. Put a lid on the pan to stop a skin forming.
For the Macaroni Ham and Cheese:
Cook the macaroni in boiling, salted water for two minutes less than the packet says. Drain well
Add the macaroni to the cheese sauce and stir to coat. Add the ham and stir gently to avoid breaking it up
Pour into the baking dish
Sprinkle the cheese and breadcrumb mix over the top
Cook for 15-20 minutes or until the top is browning and the sauce is beginning to bubble
Leave to stand for about 20 minutes out of the oven before serving.