Creole Jambalaya

Name: Creole Jambalaya
Ingredients: 2 tablespoons olive oil; 2 tablespoons butter; 3⁄4 lb boneless skinless chicken thighs, cut into 1-inch chunks; 1⁄2 lb andouille sausages or 1⁄2 lb hot Italian sausage, cut into 1/2-inch slices; 1 medium onion, diced; 2 -3 garlic cloves, minced; 1 celery rib, chopped; 1⁄2 green pepper, diced; 2 tablespoons creole seasoning; 1 tablespoon tomato paste; 1 cup canned diced tomato, with juices; 1 cup chicken stock; 12 large shrimp, deveined, shells intact; 1 cup long grain rice; 2 scallions, chopped (optional); 1⁄4 cup fresh parsley, chopped (optional)