Preheat the oven to 190°C.
Lightly oil a muffin tin. If using ham, then line each cup with one slice of prosciutto, taking care to cover the bottom and sides completely.
Beat the eggs in a large mixing bowl.
Roughly grate the courgette, then chop the parsley and mince the garlic. Add these to the egg mixture, season with salt and pepper, then toss gently.
Spoon the batter into the muffin tin, filling each cup ¾ full (you can grate some cheese on top if you like).
Bake in the oven for about 20 minutes until golden.
Let the muffins cool in the tin for a couple of minutes, then transfer them to a plate.
Serve them warm, or let them cool completely and have them as snacks.