Prepare the Greens: Rinse the greens thoroughly under cold water to remove any dirt or grit. Remove any large, tough stems and roughly chop the leaves. Set aside.
Make the Roux: In a large pot over medium heat, combine the avocado oil and flour. Stir constantly until the mixture turns a dark brown color. This is your roux, which will thicken the gumbo and give it a rich flavor. Take your time, this will take about 45 minutes.
Cook the Vegetables: Add the chopped onion, bell pepper and celery to the pot with the roux. Cook, stirring occasionally, until the vegetables have softened. Add the garlic and cook for another 30 seconds.
Add the Seasonings: Stir in the cajun seasoning, cayenne pepper, chicken base, salt, and black pepper. Mix well to ensure the seasonings are evenly distributed.
Add the Meat: Add the diced ham and sliced andouille sausage to the pot. Give it a good stir.
Add the Stock and Greens: Pour in the chicken stock, then add the chopped greens. Stir well to combine all the ingredients.
Simmer the Gumbo: Bring the mixture to a boil, then reduce the heat to low and let it simmer for about 45 minutes to an hour.
Finish the Gumbo: If you’re using file powder, stir it into the gumbo after it has finished cooking and has been removed from the heat.
Serve: Ladle the gumbo over cooked rice and serve hot. Enjoy!