01 -
Get your oven hot at 375°F (190°C)
02 -
Strip the skin off the butternut squash and cut it into skinny 1/8-inch disks. Save about 12-15 pretty slices for the top. When you hit the seed area, scoop them out and keep slicing. Maybe sort your slices into three groups to make layering easier.
03 -
Cut and wash the leeks well - the moisture will make cooking easier. Warm up oil or butter in a big pan on medium. Cook those leeks about 8-10 minutes with the lid partly on to help them get soft. Toss in garlic, sage, and a bit of salt, then cook 2-3 minutes more. Turn off the heat.
04 -
In a bowl, stir together your cream (or coconut milk) with salt, pepper, nutmeg, and onion powder if you're using it.
05 -
Coat a 9x13-inch dish or 11-12 inch round pan with some oil or butter. Pour 1/4 cup water on the bottom. Start with a layer of squash slices that slightly overlap. Add half your leeks, pour 1/3 cup of your cream mix, and sprinkle 1/3 of the cheese. Do another layer, using the not-so-perfect squash bits in this middle section. Top with your prettiest squash rounds, the rest of the cream, cheese, and all the walnuts. Press down lightly to flatten.
06 -
Cover with foil (put parchment under it) and bake for 45 minutes at 375°F. Then uncover, check if the squash feels tender, and cook at 400°F for another 15 minutes until it looks golden on top.