Preheat your oven to 400°F (200°C).

Peel and thinly slice the butternut squash into uniform pieces, about ¼ inch thick.

Melt butter in a saucepan over medium heat. Add chopped shallots and minced garlic, sauté for 3-4 minutes.

Stir in flour to form a roux, mixing for 1-2 minutes.

Gradually whisk in vegetable stock, then add heavy cream along with salt, pepper, and chopped sage leaves.

Grease a baking dish and layer with squash, creamy mixture, and parmesan cheese. Repeat layers and finish with cream and parmesan.

Cover the dish with parchment and aluminum foil, bake for 20 minutes.

Remove cover and bake uncovered for another 10 minutes until golden.

Let rest for a few minutes, garnish with chives, then serve warm.