Preheat your oven to 400°F (200°C).

In a large mixing bowl, combine diced butternut squash, carrots, parsnips, sweet potatoes, and Brussels sprouts, drizzle with olive oil, then season with salt, pepper, fresh thyme, and rosemary.

Spread the vegetable mixture on a baking sheet and roast for 25-30 minutes, tossing halfway through.

In a large pan, melt butter over medium heat, add chopped onion and minced garlic, sauté until translucent.

Stir in all-purpose flour and cook for 1-2 minutes until a roux forms.

Gradually whisk in vegetable broth and then heavy cream, ensuring the sauce thickens.

Roll out puff pastry dough on a floured surface, cut into rounds for baking bowls.

Fill baking bowls with creamy vegetable mixture, leaving space at the top, and place puff pastry over each bowl sealing edges.

Beat an egg and brush the wash over the pastry tops.

Bake the pot pies for 20-25 minutes until the pastry is golden brown.

Let the pot pies cool for about 10 minutes before serving.