First make the white sauce.
Put the milk in a saucepan, then simply add the sauce flour, butter and seasoning and bring everything gradually up to simmering point over a medium heat, whisking continuously with a balloon whisk, until the sauce has thickened and becomes smooth and glossy. Then turn the heat down to its lowest possible setting and let the sauce cook very gently for 5 minutes to take the raw taste out of the flour, stirring from time to time. Finally season and add the freshly grated nutmeg.
Meanwhile cook the macaroni in plenty of boiling salted water for 6 minutes (as it will finish cooking in the oven). Then drain the pasta and tip it into a mixing bowl and add the Ragu sauce and white sauce, along with half of the grated Parmigiano Reggiano and mix together thoroughly. Then transfer the mixture into the buttered dish and level the surface with the back of a spatula.
Sprinkle with the remaining Parmigiano Reggiano and bake near the centre of the oven for 30 minutes (or 40 minutes from chilled) until bubbling and golden.
Pasta for all our Cookery School recipes from the Martelli family, air-dried in huge lofts in Lari, Tuscany.
MARTELLI STOCKIST: Camisa Ltd.Tel: 01992 763 076 www.camisa.co.uk
Pre-heat the oven to 180°C, gas mark 4