Thaw the puff pastry dough according to package directions, keeping it cold but pliable.

Preheat the oven to 400°F (200°C) and line a baking sheet with parchment paper.

Finely chop 10 oz (283 g) spinach and mince 2 garlic cloves.

Cook the spinach and garlic in a dry skillet over medium heat until the spinach wilts, about 3 minutes.

Drain and squeeze the cooked spinach mixture thoroughly to remove excess moisture.

Chop 2 tbsp (8 g) fresh dill and crumble 4 oz (113 g) feta cheese.

Zest the lemon to obtain 1 tsp (2 g) lemon zest.

Combine the drained spinach mixture, dill, feta cheese, lemon zest, black pepper, and salt in a mixing bowl.

Roll the puff pastry dough into a roughly 10-by-12-inch (25-by-30-cm) rectangle.

Spread the spinach and feta filling evenly over the puff pastry, leaving a 1/2-inch (1-cm) border along one long edge.

Roll the pastry tightly from the long filled edge into a log, then pinch the seam closed.

Slice the log into 8 equal pinwheels and arrange them cut-side up on the lined baking sheet.

Beat 1 egg with 1 tsp (5 ml) water to make an egg wash.

Brush the tops and exposed pastry edges with the egg wash.

Bake the pinwheels for 18 to 22 minutes until puffed and deeply golden brown.

Cool the pinwheels for 5 minutes, then serve warm.