Preheat your oven to 400°F (200°C) to prepare for roasting the vegetables.

In a large mixing bowl, toss together chopped butternut squash, carrots, parsnips, sweet potatoes, and brussels sprouts with olive oil. Season with salt, pepper, thyme, and rosemary.

Spread vegetables evenly on a baking sheet and roast for 25–30 minutes, stirring halfway through.

Melt butter in a saucepan over medium heat. Add diced onion and minced garlic; sauté until translucent.

Sprinkle flour over sautéed onion and garlic and stir continuously to form a roux for 1–2 minutes.

Whisk in vegetable broth gradually; stir until thickened, then add heavy cream and mix well.

Gently fold in the roasted vegetables, adjusting seasoning as necessary.

Roll out puff pastry and cut to fit ramekins or a pie dish, leaving some overhang.

Divide the filling among ramekins, cover with puff pastry, and press edges to seal.

Create slits in the pastry to allow steam to escape.

Brush puff pastry with beaten egg or a plant-based alternative for a golden finish.

Bake pies in the oven for 20–25 minutes until the pastry is golden and puffy.

Let the pot pies cool for 5–10 minutes before serving.