Chicken & Vegetable Tray Bake

Name: Chicken & Vegetable Tray Bake
Cuisine: European, British
Ingredients: 4 chicken legs and thigh pieces*; 2 red onions, peeled and quartered; 2 red bell peppers, deseeded and cut into chunks; 2 yellow bell peppers, deseeded and cut into chunks; 200g sweet potato, peeled and cut into wedges; 100g new potatoes; 400g mushrooms; 8 unpeeled garlic cloves; few sprigs of fresh rosemary; 2 tsps dried thyme; one-calorie spray oil; juice of 2 lemons; freshly ground black pepper