Preheat oven to 425℉. Line a large baking sheet with parchment paper or a silicone baking mat. Set aside.
In a large bowl combine the cream cheese, sour cream, mozzarella cheese, parmesan cheese, grated onion, minced garlic, salt and pepper. Stir together.
Add in the spinach and artichokes. Stir until all combined.
Spread out the puff pastry, pressing to even out the fold marks, so that there are two whole sheets of pastry.
In a small bowl combine the egg and the water. Mix with a fork. Brush this onto the top of the puff pastry. Spread a layer of the spinach artichoke dip on the puff pastry.
Carefully roll it up and using a sharp knife cut into one inch sections. Lay onto the prepared baking sheet. Brush the top of the pinwheels with the egg wash.
Bake for about 20 minutes. Will be slightly golden. Remove from the oven and allow to cool for a couple minutes. Best when served warm.