Preheat your oven to 400°F (200°C).

In a large mixing bowl, combine the butternut squash, carrots, parsnips, sweet potatoes, and Brussels sprouts. Drizzle with olive oil and season generously with salt, pepper, fresh thyme, and rosemary. Toss everything together until the vegetables are evenly coated.

Spread the seasoned vegetable mixture onto a baking sheet in a single layer. Roast in the preheated oven for about 25-30 minutes, stirring halfway through, until the veggies are caramelized and tender.

While the vegetables are roasting, melt the butter in a saucepan over medium heat. Add the chopped onion and minced garlic, sautéing for about 3-4 minutes or until the onion becomes translucent.

Stir in the flour to the sautéed onion and garlic, cooking for 1-2 minutes until the mixture is lightly golden. Gradually whisk in the vegetable broth, stirring continuously. Allow it to simmer for about 5 minutes, until the sauce thickens.

Once the vegetables are done roasting, remove them from the oven and fold them into the creamy sauce. Pour in the heavy cream, mixing thoroughly.

On a lightly floured surface, roll out your thawed puff pastry until it’s about a quarter inch thick. Using a round cutter, cut the pastry into circles that are larger than your serving bowls.

Spoon the hearty vegetable filling into individual bowls. Drape the puff pastry rounds over each bowl, allowing the edges to hang over. Press the edges gently to seal.

Brush the tops of each pastry with the beaten egg. Carefully place the bowls on a baking sheet and bake in the oven for 20-25 minutes, or until the pastry is golden brown.

Once baked, remove the pot pies from the oven and let them cool for a few minutes. Serve warm.