Melt the butter in pan over medium-high heat.
Saute the celery and onion until softened, 3 to 5 minutes.
Transfer the mixture, with the drippings, to a large bowl. Add the hot sauce to the bowl and stir to combine. Add the chicken, blue cheese, salt, pepper, eggs and 1 1/2 cups of the panko and mix until well combined.
Press the mixture into the prepared loaf pan, pressing more in the center of the loaf to create a divot.
Brush the sauce over the top.
Mix the Parmesan with 1/2 cup of the panko.
Sprinkle on top of sauce.
Bake 45 -60 minutes.
Let rest 15 mins and slice.
Serve with blue cheese crumbles, celery and hot sauce.