In a sauté pan on medium heat, add some olive oil. When hot, add the broccoli. Cook until softened.
Put the Boursin in a small bowl and mash it with a fork.
In another medium bowl, add the eggs, milk, cream, and mashed Boursin. Add a pinch of salt, pepper, and nutmeg. Mix well everything with a fork. Set aside.
Take your tart pan from the fridge. Sprinkle grated parmesan all over the bottom. Put the broccoli florets evenly. Distribute pieces of Prosciutto all around the tart.
Pour the egg mixture all over the tart.
Bake at 400 F for about 25-30 minutes or until lightly brown.
Let cool for about 5-10 min before cutting.