Place ½ cup butter in a 13 x 9" pan. Heat in oven at 425 degrees for 4 minutes.
Stir together cornmeal and flour; whisk in eggs and buttermilk. Pour hot butter into batter and stir until blended. Pour batter into pan. Bake at 425 degrees for 30 minutes or until golden brown. Cool. Crumble cornbread into a large bowl. Stir in breadcrumbs and set aside.
Melt remaining ½ cup butter in a skillet over medium heat; add onions and celery, and saute 5 minutes. Stir in safe, parsley, and seasoned pepper. Saute 1 minute. Remove from heat and stir into cornbread mixture.
Whisk together chicken broth and remaining 4 eggs, stir into cornbread mixture. Pour evenly into 1 lightly greased 13x9" pan and 1 lightly greased 8" square pan.
Bake at 400 degrees for 35-40 minutes or until golden brown.