Roast Chicken with Vegetables

Name: Roast Chicken with Vegetables
Ingredients: 1 ( 4 to 4 1/2 ) pound chicken; Kosher salt and freshly ground black pepper; 6 cloves garlic , smashed and peeled (smash with the side of a chef's knife, makes it easier to peel); 6 sprigs thyme; 3 medium rutabagas , peeled, trimmed, and cut into 1/4-inch wedges; 2 medium turnips , peeled, trimmed, and cut into 1/4-inch wedges; 4 medium carrots , peeled and cut in 2-inch segments; 1 small yellow onion , peeled, roots trimmed but kept intact, cut into quarters; 8 small red-skinned new potatoes; 1/3 cup extra virgin olive oil, divided; 4 tablespoons butter , room temperature (spreadable)