Preheat & Prep: Heat oven to 400°F (200°C). Line a tray with parchment. Lay out pastry squares and poke the centers with a fork.
Sauté: In a skillet, heat olive oil. Cook shallots and garlic for 2 minutes.
Mushrooms: Add mushrooms, parsley, and sage. Cook for 5–7 minutes until dry and tender. Season with salt/pepper.
Assemble: Place mushroom mixture in pastry centers. Top with crumbled goat cheese.
Wash & Bake: Brush pastry edges with beaten egg. Bake for 15–20 minutes until golden and flaky.
Serve: Garnish with thyme and enjoy warm.