Genereously sprinkle both sides of the chicken pieces with about 4 t of the seasoning mix.
Combine remaining seasoning mix with the flour in a paper or plastic bag.
Generously dust each chicken piece with the seasoned flour.
Reservce leftover flour to make the roux.
In large skillet, heat 1 inch of oil to 230-250.
Cook chicken pieces in the hot oil, maintaining the oil's temp to a level just hot enough for the chicken to boil instead of fry.
Cook pieces of similar size together to ensure even cooking.
Boil with skin side down about 20 min, then on the other side until tender, about 15 min more.
Drain on paper towels.
Remove skillet from heat and let cool 15 min.
Pour the oil into a large glass bowl, leaving the sediment in the pan.
Pour 1/2 C of the cooled oil back into the skillet and heat over high heat.
Slowly whisk in 3/4 C of the reserved seasoned flour with a long-handled metal whisk; cook until the roux is smooth and medium colored, about 2 to 3 min, whisking constantly (don't let scorch.) Immediately stir in the onions and celery and continue cooking untiil onions are wilted, about 5 min, stirring constantly.
Remove from heat.
In a 4-qt saucepan, bring the stock to a boil.
Add the roux mixture by spoonfuls to the boiling stock, blending well between each addition.
Then add the boiled chicken pieces and the seqasonings.
Simmer uncovered over how heat for 1 hour (or longer if the chicken needs further tenderizing), stirring often.