Turn on oven to 325 Fahrenheit degrees.
Slice butternut squash length wise. Discard seeds. I like to leave the skin on because I like the texture of it roasted. You can decide to peel the skin or leave it on. Chop the butternut squash into cubes.
If you want to use parchment paper on a cookie sheet it makes it easier to clean up after. Place the butternut squash on the sheet and pour the olive oil and sea salt on top and mix well to coat. Place in the oven for 20 minutes.