Gumbo from Scratch with a Roux

Name: Gumbo from Scratch with a Roux
Ingredients: 3 boneless skinless chicken thighs ((chopped)); 1 pound Andouille sausage ((halved lengthwise and cut into 1/4-inch slices)); 1/4 cup vegetable oil; 1/2 cup all-purpose flour; 5 tablespoons butter ((divided)); 1 large yellow onion ((chopped)); 6 cloves garlic ((minced)); 1 green bell pepper ((seeded and chopped)); 3 ribs celery ((chopped)); 1/4 cup Worcestershire sauce; 2 bay leaves; 1 bunch fresh thyme; 1 tablespoon paprika; 6 cups Beef Stock; 14 ounces diced tomatoes with juice; 2 cups frozen sliced okra; 4 sliced green onions; 1/4 cup chopped parsley; 1/2 pound small shrimp ((optional, peeled, deveined)); salt and pepper to taste