Preheat oven to 400°F (200°C).

Prepare and toss the cubed butternut squash, sliced carrots, parsnips, sweet potatoes, and halved Brussels sprouts with olive oil, thyme, rosemary, salt, and pepper.

Spread vegetables on a baking sheet and roast for 25-30 minutes, turning halfway through.

Melt butter in a saucepan and sauté diced onion and minced garlic for about 5 minutes until soft.

Stir in flour and cook for 1-2 minutes to create a roux.

Gradually whisk in vegetable broth and simmer for 3-4 minutes until thickened.

Add heavy cream to the sauce and fold in the roasted vegetable mix; season to taste.

Roll out puff pastry and cut rounds for ramekins.

Divide filling into ramekins, cover with puff pastry rounds, and seal edges.

Brush tops with beaten egg for a golden finish.

Bake for 20-25 minutes until pastry is puffy and golden.

Allow to cool slightly before serving.