Marinate the chicken in the buttermilk if you have time.
Add 1 tablespoon of seasoning to the buttermilk and pour it over the chicken breast. Marinate 30 minutes.
Remove from the buttermilk and pat dry.
Mix the ½ cup flour and the Tony Chacheres seasoning (or salt and pepper).
Dredge the chicken in the flour mixture, covering all sides. To dredge the chicken in the flour just plop it down in the flour and coat one side then turn it over and coat the other. Press the flour into the chicken gently.
Heat the oil or bacon grease (or a mix) in the skillet - there should be just enough to cover the bottom with a thin layer.
Add the garlic, onions, and celery and saute for about 3 minutes, or just until they start to cook and become translucent.
Remove the vegetables from the skillet, set aside, and carefully add the chicken.
Cook for about 4 minutes, or until the bottom is golden brown, then flip and cook another 3 to 4 minutes.
Remove the chicken from the pan and set aside.
Melt the 2 tablespoons of butter in the skillet.
Whisk in the 3 tablespoons flour and reduce heat to low.
Cook, moving the flour around the pan so it doesn't scorch, for about 2 minutes.
Add the chicken stock slowly, whisking to keep it smooth.
Whisk in the milk and 1 teaspoon of Tony Chachere's seasoning.
Simmer for about 1 minute to let it begin to thicken.
Add the sauteed onion mixture and the chicken, spooning the gravy over the chicken.
Bring to a boil, reduce heat to low, cover the pan, and simmer for 20 minutes. Check and stir occasionally to ensure that it isn't boiling dry or sticking.
Serve over rice, mashed potatoes, or biscuits.
Bone in chicken will be juicier and have more flavor but it will also take a bit longer. I personally use chicken breast and it's fine.
Adjust the onions and garlic to your own tastes.
If you don't like spice use salt and pepper in place of the Tony Chachere's.
If you have time marinate the chicken in buttermilk for 30 minutes before cooking. It will make it even more tender.
If you've got a big iron skillet use it for this recipe. It' just works really well.
Be sure to pat the chicken dry before adding it to the hot pan.
Once you add the chicken to the hot pan leave it alone for about 4 minutes so it can get a nice crust before you turn it over. If the crust tears off when you flip it you turned it too quick.
You'll want the interior of the chicken to be about 160F - it will finish cooking to 165F while you are getting it one the table.
Make it super quick and easy - use commercial chicken gravy and cut up a rotisserie chicken into the gravy - simmer for 10 minutes. Is it as good? No, but it's still good - and sometimes you need something ultra quick.