Roast Chicken with Chestnuts and Orange Yam Mash

Name: Roast Chicken with Chestnuts and Orange Yam Mash
Ingredients: 1 bulb fennel (cut into 8 large wedges); 6 cipollini onions (peeled and halved); 1 4- to 5- pound whole organic chicken; 1-2 tablespoon kosher salt; Freshly ground black pepper; 6 sprig fresh thyme or 1 tablespoon dried thyme; 2 tablespoon extra virgin olive oil ( such as Colavita); 1 3.5-ounce bag roasted chestnuts; 3 yams or sweet potatoes (peeled and cubed); ¼ cup orange juice; 2 tablespoons vegan butter or coconut oil