-Position 1 rack in the bottom third of your oven and 1 rack in the center of the oven.
-Preheat your oven to 400 degrees.
-Grease 2 large heavy baking pans.
-Peel and cut into 1-inch pieces any of the following:
-Unpeel 1 head of garlic, leaving the cloves whole.
-In a large bowl combine all the vegetables except the garlic.
-Toss with ¼ cup olive oil and a sprinkle of fresh or dried rosemary.
-Divide the vegetables between the baking sheets and roast for 30 minutes.
-Stir, add the garlic, and then reverse the baking sheets in the oven.
-Continue to roast until all vegetables are tender and brown, stirring occasionally, about 45 minutes more.