Trim the ends: Place the butternut squash on a sturdy cutting board. Using a sharp chef’s knife, carefully cut about 1/2 inch off the top and bottom ends to create two flat surfaces.
1 butternut squash
Separate the neck from the rounded base: Butternut squash has two sections: one is the top section on the stem-end side, which is narrower and filled with solid flesh. The second section is more rounded and bulbous; it is hollow and contains the seeds. So you’ll lay the squash on its side and cut crosswise where the long neck meets the rounded, bulbous base to make 2 sections, because working with 2 smaller pieces makes the squash much easier and safer to handle.
Peel the squash: Stand each piece upright on a flat cut side. Use a sturdy vegetable peeler to remove the skin, working from top to bottom. Go over the squash a second time anywhere you still see pale green or white streaks beneath the skin. You want to expose the bright orange flesh.
Cut the bulb in half: Stand the rounded bottom portion upright on its flat end and carefully slice it in half from top to bottom.
Scoop out the seeds: Use a sturdy spoon to scoop out the seeds and stringy pulp from each half. Discard them or save the seeds for roasting.
Slice the squash: Cut the peeled neck into approximately 1-inch-thick rounds. Cut the seeded bottom halves into slices approximately 1 inch thick.
Cut into cubes: Cut the slices into strips, then cut crosswise into approximately 1-inch cubes. Try to keep the pieces relatively uniform, so they cook at the same rate.