How to Make a Cajun crawfish etouffee straight out of the French Quarter

The longer you let this New Orleans classic sit, the better it will taste. For this dish, you will need: 2 sticks butter, 1 cup olive oil, 3 chopped onions, 3 stalks celery, 2 green peppers, 10 cloves of garlic, 2 bay leaves, 1 can Rotel tomatoes, 1 can diced tomatoes, 2 tablespoons Worcestershire sauce, salt, cayenne pepper. juice from 1 lemon, 3 pounds peeled crawfish tailes, 1/2 cup chopped parsley and 1/2 cup chopped scallions.