Prep the butternut squash: Peel and thinly slice the butternut squash into half rounds. When you get to the seeds, scoop them out and continue slicing the flesh, or keep the bottom of the squash for another recipe.

In a small saucepan, melt butter and cook the shallot and garlic until fragrant, 1 or 2 minutes.

Add flour and whisk with a wooden spoon to make a roux. Butter and flour will combine and increase in volume.

Whisk in the vegetable stock progressively, whisking continuously.

Add cream, pepper, onion powder, and sage leaves. Continue stirring the cream sauce without boiling until smooth.

Layer the butternut squash gratin: Grease a 9 x 13-inch baking dish with a small knob of butter. Drizzle with ⅓ of the cream mixture to the bottom of the pan, sprinkle with a bit of parmesan, then arrange the butternut squash slices in 2 or 3 rows, overlapping slightly.

Drizzle the butternut slices with the remaining ⅔ cream mixture. Cover the gratin, using parchment paper first as a barrier, under the foil if the foil touches the top of the gratin.

Bake the butternut squash gratin for 20 minutes covered.

Remove the baking dish from the oven, uncover it, and sprinkle parmesan cheese on top. Bake at 400ºF (200ºC) uncovered for 10 minutes until golden and crispy.

Remove the butternut squash gratin from the oven, sprinkle with fresh chives, and serve 'family style' immediately. Enjoy!