Start by making your roux. In a large, heavy-bottom stock pot, combine the flour and canola oil over medium-low heat. Stir continuously for about 30 to 45 minutes. This is the key step—patience is essential here. You want it to develop a rich, dark chocolate color with a consistency akin to soft cookie dough, without burning. If needed, adjust the flour or oil to reach that ideal texture.

While your roux is cooking, grab a separate skillet and heat it on medium-high. Arrange the sausage slices in a single layer and allow them to brown well, about 2-3 minutes per side. Once done, transfer them to a plate.

In the same skillet where you browned the sausage, pour in half a cup of the chicken broth to deglaze the pan, scraping up any flavorful bits stuck to the bottom. Add this liquid to your large pot with the roux. Now, toss in the diced celery, chopped onions, bell peppers, parsley, garlic, and the remaining chicken broth. Stir well to combine everything.

Increase the heat to medium, allowing the mixture to come to a gentle boil. Let it simmer for about 5-7 minutes or until the veggies are just beginning to soften. You may want to skim off any foam that rises to the top. Stir in the Cajun seasoning to taste.

Now it's time to bulk up your gumbo. Add the shredded chicken, browned sausage, and cooked shrimp.

Finally, taste your gumbo and season it according to your preferences. Whether it’s more salt, pepper, or a dash of garlic powder, adjust until it’s just right. Serve warm, over a generous scoop of rice. And believe me, leftovers make this dish even better the next day!