Step 1

Place a large, heavy-bottomed skillet over medium-low heat. Add the butter. When the butter is completely melted and begins to foam, incorporate the flour, whisking constantly. Continue whisking, being careful to scrape the entire bottom and sides of the skillet to prevent burning, about 20 minutes, or until the roux develops a light peanut butter color and a nice, nutty smell.

Step 2

Add the onions, celery, green bell pepper, and garlic. Sauté, stirring frequently, for about 5 minutes, or until the onions begin to look translucent. Watch carefully to be sure that the roux does not burn during the sauté.

Step 3

During the last minute of sautéeing the vegetables, add the cayenne (if using), salt, black pepper, Cajun/Creole seasoning, and bay leaves. Stir to combine.

Step 4

Slowly add the diced tomatoes with juices and the stock, stirring vigorously to incorporate the liquid into the roux. Bring the mixture to a boil, then reduce the heat and simmer for 25 minutes. Taste the sauce: if it's too bland for your taste, mix in a bit more Cajun/Creole seasoning and/or salt. Remove sauce from heat and let cool for 10-15 minutes; refrigerate in an airtight container up to 2 days.

Step 5

Reheat the sauce in a heavy-bottomed skillet over medium-low heat, stirring occasionally, about 25 minutes.

Step 6

If you like, season the shrimp with the remaining 1/2 teaspoon of Cajun/Creole seasoning. Stir the shrimp into the sauce (or see Recipe Note 3); simmer until cooked through, about 3-6 minutes (check the cut side of the shrimp: the flesh should be opaque and slightly white rather than translucent, but not bright white.

Step 7

Taste the sauce for seasoning, adding additional salt or Cajun/Creole seasoning as necessary (see Recipe Note 2). Remove the skillet from the heat. Add 1 tablespoon of cold butter to the sauce, stirring to incorporate. Remove the bay leaves and discard. Serve the etouffee with the garnishes, condiments, and rice.