Sprinkle 4 teaspoons of the Poultry Magic evenly all over the chicken and rub it in.
Combine the flour with 4 teaspoons Poultry Magic in a paper or plastic bag. Add the seasoned chicken pieces and shake until the chicken is well coated. Reserve the leftover seasoned flour to make the roux.
In a large skillet, heat 1 inch of oil to between 230° to 250° and add the chicken. Use an electric skillet or cooking thermometer and adjust the heat to keep the oil's temperature at a level just hot enough for the chicken to boil instead of fry. This tenderizes the chicken and brings the gelatin from within the bones to the surface. Cook pieces of similar size together to ensure even cooking. Boil with the skin side down for 20 minutes, then on the other side for 15 minutes more. Drain the chicken on paper towels.
Remove the skillet from the heat and let cool for 15 minutes. Pour the oil into a large glass bowl, leaving the sediment in the pan. Pour ½ cup of the cooked oil back into the skillet and place over high heat. Slowly whisk in ¾ cup of the reserved seasoned flour and cook, whisking constantly, until the roux is smooth and medium-brown, about 2 to 3 minutes, being careful not to let it scorch or splash on your skin. Immediately stir in the onions and celery and continue cooking, stirring constantly, until the onions are wilted, about 5 minutes. Remove from the heat.
Bring the stock to a boil in a 4-quart pot and add the roux by spoonfuls, blending well after each addition. Add the chicken pieces and remaining 4 teaspoons of Poultry Magic, reduce the heat to low, and simmer, uncovered, stirring often, for 1 hour. Check the chicken for tenderness and simmer longer if necessary. When tender, serve over the rice or with the boiled potatoes.