01 -
Finely chop the mushrooms and onion.
02 -
In a large skillet, heat olive oil over medium-high heat and sauté the onion until translucent, about 3-4 minutes.
03 -
Add the chopped mushrooms to the skillet and cook until they release their moisture and are thoroughly cooked, approximately 5-7 minutes.
04 -
Add mayonnaise, salt, black pepper, minced garlic, and Parmesan cheese to the mushroom mixture. Stir thoroughly to combine all ingredients.
05 -
Roll out each sheet of puff pastry to approximately 30 x 40 cm (12 x 16 inches).
06 -
Divide the mushroom filling evenly between both pastry sheets, spreading in a thin, even layer across the entire surface.
07 -
Sprinkle the mozzarella cheese evenly over the mushroom mixture on both sheets.
08 -
Starting from the longer edge, tightly roll each pastry sheet into a log.
09 -
Line a baking sheet with parchment paper. Place both rolls on the sheet and brush generously with beaten egg.
10 -
Using a sharp knife, cut each roll into 2.5 cm (1 inch) thick pinwheels. Arrange the pinwheels flat on the parchment paper, leaving space between each.
11 -
Bake in a preheated oven at 185°C (365°F) for 30-40 minutes, or until the pinwheels are puffed and golden brown.