Shrimp Etouffee

Name: Shrimp Etouffee
Prep time: 20 min
Cook time: 2 h
Total time: 2 h 20 min
Cuisine: American, Cajun And Creole
Ingredients: 6 tablespoons unsalted butter; 1/2 cup all-purpose flour; 4 cups chopped onions; 2 cups chopped green bell peppers; 2 cups chopped celery; 2 tablespoons minced garlic; 1 (14.5-ounce) can diced tomatoes; 2 bay leaves; 2 teaspoons salt; 1/2 teaspoon cayenne pepper; 2 tablespoons Essence, recipe follows; 1 quart shrimp stock, recipe follows; 3 pounds medium shrimp (21 to 25 count per pound), peeled and deveined; 1/4 cup chopped parsley leaves; Steamed white rice, for serving; 1/2 cup thinly sliced green onion tops, for garnish; 2 1/2 tablespoons paprika; 2 tablespoons salt; 2 tablespoons garlic powder; 1 tablespoon black pepper; 1 tablespoon onion powder; 1 tablespoon cayenne pepper; 1 tablespoon dried oregano; 1 tablespoon dried thyme; 1 pound (about 1 quart) shrimp shells and heads; 1 cup coarsely chopped yellow onions; 1/2 cup coarsely chopped celery; 1/2 cup coarsely chopped carrots; 3 smashed garlic cloves; 1 bay leaf