Preheat the oven to 450°F. Line a large, rimmed baking sheet with high-heat-resistant parchment paper or nonstick foil.
Cut the broccoli stalk off and peel its rough outer layer with a vegetable peeler.
Slice the stalk into ¼-inch thick rounds.
In a bowl, toss the rounds with olive oil, salt, pepper, and garlic powder.
Spread the rounds on the prepared baking sheet in a single layer.
Roast until golden brown, about 10 minutes per side. Serve immediately.
Video
Notes
It's best to use two baking sheets, one for the broccoli florets and one for the stems. The florets will be ready faster than the stems. At 450°F, the stems need about 20 minutes in the oven, while the florets should be ready after 10-15 minutes.
You can keep the leftovers in an airtight container in the fridge for 3-4 days. Reheat them in the microwave at 50% power or in a 350°F oven. They are also excellent cold, straight out of the fridge.