Heat a medium skillet over high heat. Add the andouille and cook until golden brown on both sides. Remove to a plate lined with paper towels. Do not drain
. In the same pan, cook the celery, carrots, onion, bell pepper and garlic until soft.
the butter over medium heat in a large Dutch oven
. Gradually add the flour, stirring occasionally. Cook the mixture (roux) until it's a light-caramel color, about 5 to 7 minutes. Add the onion mixture and cook for about 3 minutes, without stirring.
Bring the stock to a boil in a large saucepan. Whisk
in about 6 cups of the stock
into the roux
mixture. Bring to a boil, then reduce the heat to a simmer
, add the andouille sausage and continue simmering for about 20 minutes, add more stock if the mixture is too thick. Season with salt and pepper, to taste.