- Preheat the oven to 400 degrees F
- Cut vegetables into pieces that are uniform in size.
- Mix olive oil and Italian seasoning, salt, onion, and garlic powder in a large bowl until combined.
- Add vegetables to the bowl and mix until well-coated.
- Grease a baking sheet with cooking spray.
- Spread vegetables evenly onto the prepared baking sheet.
- Roast in the preheated oven until vegetables are tender, 20 to 30 minutes.
- Serve hot.