Cook the pasta for 2 minutes less than the packet says, adding the peas for the last 3 minutes; drain.
For the béchamel, cook the flour in the butter for 1 minute, whisk in the milk, cook until thick and season with salt and nutmeg.
Mix the pasta with two-thirds of the béchamel, the ham, mozzarella and half the Parmesan.
Spread in a buttered dish, spread the rest of the béchamel on top and sprinkle with the remaining Parmesan.
Bake at 200 °C for 25 minutes until golden; packed in portions it keeps 3-4 days; it heats through in the microwave in 1.5-2 minutes (and can be eaten cold).
A Receptnaptár original recipe. Calories and protein are estimated.