Preheat oven to 350°
In a large oven-proof pan, sprayed with cooking spray, spread cornbread and bread in the bottom.
In a medium sized skillet over medium-high heat, melt butter. Add celery and onion and cook until the vegetables are soft, about 5-8 minutes.
Add cooked celery and onions to bread mixture along with the brisket, poultry seasoning, jalapenos, jalapeno juice, salt and pepper. Stir in chicken stock until the mixture is soupy. Mix thoroughly. The amount of chicken stock you use will depend on how dry your bread is and the weather (if it is humid or dry outside).
Cook in oven for 1- 1 1/2 hours or until it is set and the top is golden brown. Stir half way through the cooking process. Do not over cook or you will dry it out and there is nothing worse than dry dressing.