In a shallow dish whisk together flour, baking powder, baking soda, and dry seasonings. In a second shallow dish whisk together milk, eggs, and hot sauce until smooth.
In a cast iron skillet or fry-safe pan/pot on stove over medium-medium high, heat oil (a few inches deep) until it reaches about 350 degrees. Dredge the chicken while it comes up to temp.
Flour-egg-flour: Fully coat each chicken breast in the flour mixture, dip into the egg mixture (not letting it drip off first), than back into the flour mixture. Allow excess egg mix to transfer to the flour dish, making sure to press down flour to get stuck on the chicken real good. Put finished pieces on a foil/parchment lined baking sheet.
Place chicken in hot oil and fry on each side 3-5 minutes until golden brown, remove and drain directly on a cooling rack atop a papertowel lined baking sheet. Do not place directly on paper towels as it will make chicken soggy. (Place chicken tray in the oven at 200 degrees if you want to keep it warm while you prep gravy and finish up side items.)
To make your gravy, in a saucepan add oil + pan bits, butter and heat on medium, stir in your flour until absorbed and cook for about 1 minute (it'll bubble slightly).
Slowly add in your milk whisking to blend and heat until thickened then stir in seasonings until it's nice and seasoned. This part is very important as all the flavor is in the salt, pepper and poultry seasoning. **
To serve, plate your chicken and pour spoonfuls of gravy directly over each piece (and over the potatoes if serving).