Mahogony Risotto with Two Celeries

Name: Mahogony Risotto with Two Celeries
Ingredients: for mahogony broth; 4-5 pound roasting chicken; 3 carrots; 4 celery stalks; 1 yellow onion; 2 turnips; 4 garlic cloves; 2 tablespoons vegetable oil; for the risotto; 1 tablespoon butter; 1 tablespoon olive oil; 1/2 onion, diced; 1 cup Arborio rice; 1/4 cup dry white wine; 8 ounces celey root, grated fine to make 1 cup; 2 1/2 cups mahogony chicken broth; 1 1/2 cups chopped celery; 1 cup grated Parmesan cheese; few drops lemon juice; salt and pepper