First off, you will take the puff pastry roll out of the fridge and let it come to room temperature.
Turn on the oven to 180C to preheat.
In the meantime, peel the butternut squash and core it, then remove the seeds and slice thinly. Set it aside. Cut the Brie as well, then wash your sage leaves and dry them properly.
Get the puff pastry, place it on a baking dish over parchment paper and create a border by folding the outside of the circle inwards.
Layer the butternut squash and brie slices circularly, alternating between them.
Drizzle everything with olive oil, including the crust, then add the sage leaves and brush with some extra olive oil.
Bake for 25-30 minutes or until golden.
Serve the brie galette immediately.