Παστίτσιο με πλούσια κρέμα
About 1 3/4 lbs cooked ground beef (I usually make a double batch of my meat sauce recipe and use the leftovers after we've had spaghetti with meat sauce once) • parsley, finely chopped • pastitsio pasta (or ziti) • salt • grated hard cheese (like Parmesan or Romano) (about 100 grams) • milk (1.5 liters) • butter (about 150 grams) • all-purpose flour (about 150 grams) • Salt • Freshly ground black pepper • nutmeg • eggs •