Heat 1/4 cup oil in a large pot.
Add 1 cup flour to a large bowl and stir in 1 teaspoon Cajun seasonings (and salt and pepper to taste, if desired).
Dredge the chicken in the flour mixture, then sear the chicken in the hot pot until the skins start to brown, about 5 minutes per side. Remove the chicken and set aside for now. Discard seasoned flour.
Add the remaining oil and stir in 1/2 cup flour to form a white batter. This is your roux. Cook, continuously stirring, until the roux darkens to the color of light chocolate. This should take about 20 minutes. It is important to keep stirring. Do not let the roux burn at the bottom of the pot.
Add the onion, peppers and celery. Stir and cook for 5 minutes to soften.
Add the garlic and remaining 1 tablespoon of Cajun seasonings. Stir and cook for 1 minute.
Stir in the chicken stock, bay leaf and hot sauce to taste.
Add the chicken back to the pot and cover. Reduce the heat and simmer for 30 minutes, or until the chicken is falling off the bone.
Serve! I like to serve mine over white rice or with cooked noodles.