These flaky spinach pinwheels use puff pastry, chopped spinach, smooth-melting fontina cheese, and bits of sun-dried tomato to make a light, savory bite for the perfect appetizer platter.
Thaw the spinach completely, then squeeze out as much liquid as possible using a fine-mesh strainer or cheesecloth (see notes). Transfer to a mixing bowl and add the sun-dried tomatoes, balsamic vinegar, and grated fontina.
Season the mixture with salt, pepper, and a pinch of garlic powder, then mix until the ingredients are evenly combined. Set aside.
Working with one sheet of puff pastry at a time, unfold it onto a lightly floured surface and gently roll to smooth the creases without thinning the dough too much. Spread half of the filling evenly over the surface, keeping a 1/2-inch border on all sides.
Starting from a long edge, roll the pastry into a tight log, taking care not to stretch the dough, and press lightly along the seam to seal. Repeat with the second sheet and remaining filling.
Wrap each log in plastic wrap and freeze for 30 minutes, or until firm enough to slice cleanly.
Heat the oven to 400°F and line a baking sheet with parchment.
Unwrap the chilled logs and use a sharp or serrated knife to cut them into 1/2-inch slices. Arrange the pinwheels on the prepared baking sheet, leaving a little space for the pastry to puff.
Bake for 8 to 10 minutes, or until the pinwheels are golden brown and the pastry is fully puffed. Serve warm.
Notes
Dry the spinach thoroughly - This step is crucial because moisture in the filling will prevent the puff pastry from crisping. Keep squeezing or pressing until the spinach feels compact and no liquid drips out.Make-ahead tip - You can make the filling for these pinwheels up to a day in advance. We don't recommend finishing them and reheating as the layers in the puff pastry collapse and toughen.