Sprinkle the chicken evenly with 2 tablespoons of the Poultry Magic (or 1 tablespoon plus 1 teaspoon of Meat Magic) and rub it in well. Let stand at room temperature while you dice the vegetables.
Combine the onions, bell peppers and celery in a bowl and set aside.
Combine the remaining Poultry Magic (or Meat Magic) with the flour in a paper or plastic bag. Add the seasoned chicken pieces and shake until the chicken is well coated. Reserve ½ cup of the seasoned flour. Heat 1½ inches of oil in a large, heavy skillet over high heat until very hot (375°F to 400°F), about 6 to 7 minutes. Fry the chicken, skin side down and large pieces first, until the crust is brown on both sides and the meat is cooked, about 5 to 8 minutes per side. You may have to fry the chicken in batches. Drain on paper towels. Carefully pour the hot oil into a heatproof glass measuring cup, leaving some of the brown bits in the pan, then return ½ cup of the hot oil to the pan.
Return the pan to high heat and gradually whisk in the reserved ½ cup seasoned flour. Cook, whisking constantly, until the roux is dark red-brown, about 3½ to 4 minutes, being careful not to let it scorch or splash on your skin. Remove the pan from the heat and immediately add the vegetables, stirring constantly until the roux stops getting darker. Place the pan over low heat and cook, stirring constantly and scraping the pan bottom well, until the vegetables are soft, about 5 minutes.
Meanwhile, bring the stock to a boil in a 5½-quart saucepan or Dutch oven. Add the vegetable mixture by spoonfuls to the boiling stock, stirring between each addition until the roux is dissolved. Return to a boil, stirring and scraping the pan bottom often. Reduce the heat to low, stir in the Andouille and garlic, and simmer uncovered for 45 minutes, stirring often toward the end of the cooking time.
While the gumbo is simmering, pull the cooked chicken off the bones with your fingers and set it aside. When the gumbo has cooked for 45 minutes, stir in the chicken.
Serve immediately. To serve as a main course, mound 1/3 cup cooked rice in the center of a low soup bowl, and ladle about 1¼ cups gumbo around the rice. For an appetizer, place 2 heaping tablespoons cooked rice in a cup and ladle about ¾ cup gumbo on top.
NOTE: Adjust the seasoning if desired with additional Poultry Magic or Meat Magic.