Place the puff pastry on the counter to thaw.

Melt the butter in a large frying pan over medium heat. Add the onions and stir often until soft and golden.

Wash and dry the spinach thoroughly, and then roughly chop.

When the onions are done, add the garlic and cook for about 30 seconds, until fragrant.

Add the spinach along with black pepper to taste. Use tongs to constantly stir and turn the spinach just until wilted.

Place the spinach, cream cheese, herbs, onion flakes, and salt in a large bowl. Mix well with a fork.

Once the puff pastry is soft enough to handle, unfold the sheets and place on a lightly floured surface.

Divide the cream cheese mixture between the two sheets of puff pastry, lightly spreading to cover the entire surface.

Beginning with one edge, roll each pastry sheet into a log. Place the pastry on a parchment paper lined baking sheet and transfer to the fridge. Chill for at least 30 minutes.

Preheat the oven at 400ºF.

Remove the pastry from the fridge and cut into ½-inch slices. Place the slices back on the parchment lined baking sheet and bake for about 25 minutes or until golden.

Set aside for a few minutes and serve warm.

The pinwheels can be refrigerated in an airtight container for 2-3 days and also be served cold.

If using frozen spinach, let it thaw and then squeeze well to remove as much excess moisture as possible.