Heat the fat in a saucepan and sauté the flour while stirring. Add the stock and milk while stirring and bring to the boil. Add processed cheese, stir in and simmer at low heat for about 5 minutes.
Cook the pasta in plenty of boiling salted water according to the instructions on the packet. Add frozen peas approx. 1 minute before the end of the cooking time and cook for approx. 1 minute. Pour into a sieve and drain.
Wash parsley, shake dry and chop finely. Dice ham. Stir parsley and ham into the cheese sauce and season with salt and pepper.
Grease ovenproof moulds. Mix the pasta with about half of the cheese sauce and distribute into the ramekins. Pour the rest of the sauce over the pasta. Put the cornflakes in a freezer bag, crumble them coarsely and pour over
Bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for about 25 minutes.