Creating these tarts is easy if you follow these simple steps:

1. Preheat the Oven: Preheat your oven to 400°F (200°C).
2. Prepare Puff Pastry: Roll out the puff pastry sheet on a floured surface. Cut it into squares or circles that fit your tart pans.
3. Prepare the Filling: In a skillet over medium heat, add olive oil. Sauté the sliced shallots for 3-4 minutes until translucent.
4. Add Mushrooms: Toss in the sliced mushrooms and cook until they release their moisture and become tender, around 5-6 minutes. Season with salt, pepper, and thyme.
5. Mix Cheese: In a bowl, combine the herbed goat cheese and beaten egg. Stir until smooth.
6. Assemble the Tarts: Place the pastry in the tart pans and fill with the cheese mixture. Top with the mushroom and shallot mixture.
7. Bake: Place the tarts in the preheated oven and bake for about 25-30 minutes until golden and puffed up.
8. Cool: Let the tarts cool in the pan for 5-10 minutes before removing them gently.
9. Garnish: Optionally, drizzle with balsamic glaze for added flavor before serving.

These steps will help you create the incredible Mushroom Shallot and Herbed Goat Cheese Tarts effortlessly.