Lay the puff pastry sheet out on a cutting board or a lightly floured surface. Roll it out to even out the bumps, if needed.
In a medium bowl, mix the spinach, ricotta, cheeses and red pepper. Spread this mixture on the puff pastry, leaving about ½-inch border all the way around. Sprinkle with salt and pepper.
Roll one side of the puff pastry into the center. Then start from the other side and roll that into the center. Wrap it tightly with plastic wrap and place it in the freezer until semi-firm (about 30 minutes).
Preheat the oven to 400 degrees F. With a very sharp knife, cut about ½-inch slices and place them on a baking sheet. Bake for 20 minutes, or until cooked through and golden. Serve immediately or at room temperature.