Bring a pot of generously salted water to the boil. Cook the macaroni until al dente. Drain the pasta and run it under cold water until cool, set to the side for later. Preheat the oven to 200c.
Melt the butter in a large pot over medium heat. Add the flour and mix to make the roux, cook for 2-3 minutes mixing slowly but constantly, making sure there are no lumps. Add 1 quarter of the milk and whisk rigorously, once the sauce begins to thicken whisk in a little more milk. Keep doing this until you have incorporated all the milk. Gently bring the béchamel sauce to boil, whilst slowly stirring. When it starts to bubble, turn the heat down to very low.
Gently stir in 4/5th of cheese, adding a little at a time. Once the sauce is smooth, stir in the mustard & paprika. Taste and season with salt & white pepper. Add the macaroni and mix.
Transfer to an ovenproof dish, sprinkle a layer of cheese then a layer of breadcrumbs on top and bake for 30 minutes or until the top is golden brown.
Serve fresh from the dish/pot.
Notes
Pick & choice your favourite cheese to add to this replace
Try baking sliced tomatoes on top of the breadcrumbs