1 Preheat oven to 425º.2 In a large bowl combine oil, rosemary, salt and pepper until well blended.3 Add chicken, mushrooms, potatoes, onions, red bell pepper and garlic; toss until well coated. Divide mixture into two baking or roasting pans.4 Roast until chicken and vegetables are tender, about 30 minutes, stirring occasionally and rotating pans on shelves once during roasting.