Ham and leek macaroni cheese recipe

Ingredients
2tsp olive oil
4 leeks, finely sliced
600ml semi-skimmed milk
1tsp English mustard
75g blue cheese
2tsp cornflour
130g ham
300g rigatoni pasta
50g cheddar

Put a splash of olive oil in a medium saucepan over a low heat, add the leeks and sweat until softened. Pour in the milk and bring to the boil, add the mustard and the blue cheese and simmer for 5 minutes. Mix the cornflour and 2 tsp water in a bowl then whisk into the milk mix. Stir until thickened and season to taste. Chop the ham into pieces and stir through. Cook the pasta according to the pack instructions (until firm to the bite) then drain off and run under cold water. Mix in with the sauce. Pour the pasta into a large ovenproof dish and top with grated Cheddar cheese. Grill under a medium grill until golden.