Preheat oven to 400 degrees. Line a rimmed baking sheet with parchment paper or aluminum foil for easy cleanup.
Peel butternut squash and cut in half lengthwise. Scoop out the seeds and discard. Cut into 1 1/2-inch cubes.
In a large bowl, add butternut squash. Drizzle with olive and sprinkle with thyme and salt and pepper to taste. Toss until evenly coated. Spread in an even layer on prepared baking sheet.
Roast until the squash is tender and starting to caramelize, about 40 to 45 minutes, stirring after 30 minutes.
Squash: Choose a butternut squash that is firm to the touch and doesn't have any soft spots. For more information on prep, see my full tutorial on how to cut butternut squash.
Thyme: Fresh rosemary and sage are also delicious on squash.
Yield: 2 pounds butternut squash yields about 4 cups, peeled and cubed, enough for four 1-cup servings.
Storage: Store leftovers covered in the refrigerator for up to 4 days. Leftover roasted butternut squash is great tossed into salads, meal prep containers, or reheated as a side dish the next day.
Make ahead: The butternut squash can be peeled, seeded, and cubed up to 2 days in advance. Store covered in the refrigerator.
Uniform size: Make sure that the pieces are all about the same size, so they cook evenly. For squash, aim for bite-sized 1 1/2-inch pieces.
Roast the halves: If you're making mashed or puréed squash, cut the squash in half, rub the sides with olive oil, season with salt and pepper, and roast cut-side down for 45 minutes to 1 hour. For more information, see my tutorial on How to Cook Spaghetti Squash (it works the same way).
High temperature formula: I like to roast every vegetable at 400 degrees and just adjust the baking time, keeping an eye out for signs of doneness such as caramelization. But remember the Farenheit 451 rule: books burn at 451 degrees, and so does parchment paper. That's why I chose 400 degrees as my baseline, even though some vegetables could be done quicker at a higher temp.
Keep things dry: Water-logged veggies = more steam which prevents things from browning.
Crowd control: Vegetables need room to touch the baking sheet surface in order to brown, so don't let them get too crowded. Use two sheet trays if you're cooking a lot.
Yogurt sauce: A high-quality plain yogurt mixed with fresh garlic, olive oil, and fresh herbs makes a tasty sauce for roasted vegetables of all kinds.