01 -
Finely chop the onion and mushrooms. Mince the garlic.
02 -
Heat olive oil in a skillet over medium-high heat. Add chopped onion and sauté until translucent, about 3–4 minutes.
03 -
Add the chopped mushrooms to the pan and cook, stirring frequently, until moisture evaporates and mushrooms are cooked through, about 8 minutes.
04 -
Add mayonnaise, salt, black pepper, minced garlic, and grated Parmesan to the mushrooms. Stir well to combine, then remove from heat and let cool slightly.
05 -
On a lightly floured surface, roll out two sheets of puff pastry to 12 by 16 inches each.
06 -
Divide the mushroom mixture in half and spread a thin, even layer over each pastry sheet. Sprinkle shredded mozzarella evenly on top.
07 -
Starting from the long edge, roll each sheet tightly into a log.
08 -
Line a baking sheet with parchment paper and place the rolls seam-side down. Generously brush the tops with beaten egg.
09 -
Cut each roll crosswise into 1-inch pinwheels and place each piece flat on the prepared baking sheet.
10 -
Bake in a preheated oven at 365°F for 30 to 40 minutes, until the pinwheels are golden brown and puffed.