Preheat oven to 400F. Spray or brush a baking pan with olive oil.
Brush the jerusalem artichokes with a vegetable brush under water to clean them, leaving the skin on. Chop them into even 1 inch pieces.
In a large bowl, combine the chopped jerusalem artichokes, olive oil, salt, pepper, and garlic powder. Toss to coat all the pieces. Place the artichokes on a large baking sheet, making sure not to crowd them. Roast for 17-20 minutes, or until they are fork-tender. Garnish with fresh parsley and enjoy!
You can roast Jerusalem artichokes longer than 20 minutes (try 25 - 35 minutes) if you like your vegetables softer instead of crunchy.