Preheat your oven to 400°F (200°C).

In a large skillet over medium heat, add olive oil and sauté chopped mushrooms with salt and pepper for about 5–7 minutes until tender.

On a lightly floured surface, roll out your thawed puff pastry into a rectangle about 12x16 inches.

Place the sautéed mushrooms along the center of your rolled-out pastry and sprinkle cheese over the top. Create slits along each side and fold them over the filling to form a braid.

Transfer the assembled braid to a parchment-lined baking sheet, brush with egg wash, and bake for 20–25 minutes until golden brown.

Let the braid cool for about 5 minutes before slicing and serving warm.