Preheat your oven to 400°F. You can also use the convection roast function on your toaster oven (which I prefer).
Butternut squash can be a pain in the posterior to cut up. The secret to chopping it up with ease is to cut off both ends and peel the skin with a sharp vegetable peeler before hacking away at it. Peel, seed, and chop your squash into uniform pieces and place them on a parchment paper or aluminum foil-lined baking sheet.
Melt 2-3 tablespoons of ghee or your favorite cooking fat in a bowl in the microwave.
Toss the squash with the melted fat, salt, and pepper.
Roast the squash for ~45 minutes, tossing the squash every 15 minutes or so. The squash are done when you can pierce the pieces with a fork and they have browned edges. Yum!