Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.

In a large mixing bowl, combine the butternut squash, carrots, parsnips, sweet potatoes, and Brussels sprouts. Drizzle with olive oil, sprinkle with salt and pepper, and toss until well coated.

Spread the vegetable mixture evenly across the prepared baking sheet and roast for 25-30 minutes until tender and caramelized, stirring halfway through.

Melt butter in a large skillet over medium heat. Add diced onions and minced garlic, cooking for about 5 minutes until translucent.

Stir in the all-purpose flour with the sautéed onion and garlic to create a roux. Cook for 1-2 minutes without browning.

Gradually whisk in vegetable broth, stirring until the mixture thickens, about 3-4 minutes.

Once thickened, stir in the heavy cream and the roasted vegetables. Season with additional salt and pepper to taste.

Roll out the thawed puff pastry on a lightly floured surface and cut into rounds larger than your bowls.

Fill oven-safe bowls with the roasted vegetable mixture and top each with the puff pastry rounds, pressing down on the edges to seal.

Beat the egg and brush it onto the surface of the pastry.

Bake the pot pies for 20-25 minutes on a baking sheet until the pastry is puffed and golden brown.

Allow the pot pies to cool slightly before serving.