Preheat your oven to 400°F (200°C).

In a large mixing bowl, combine the diced butternut squash, carrots, parsnips, sweet potatoes, and halved Brussels sprouts. Drizzle with olive oil, and sprinkle with salt, pepper, thyme, and rosemary. Toss until evenly coated.

Spread the vegetables on a lined baking sheet. Roast for 25-30 minutes until caramelized and tender.

Melt butter in a skillet over medium heat. Add chopped onion and minced garlic, cooking for about 5 minutes until the onion is translucent.

Stir in the flour, cooking for 1-2 minutes.

Whisk in the broth and bring to a simmer. Allow it to thicken for 3-4 minutes.

Carefully stir the roasted vegetables into the roux along with the heavy cream. Taste and adjust seasoning.

Roll out the puff pastry and cut out circles for your ramekins.

Divide the filling into each ramekin and cover with the pastry rounds, sealing edges.

Beat the egg and brush over the pastry. Create small slits for steam to escape and bake for 20-25 minutes.

Let the pot pies cool slightly before serving.