Dry the Breads: Prepare your cornbread (either homemade or Martha White hot rise mix) and let it sit out to dry for a day or two. Cut or tear the 10 slices of sandwich bread into ½ inch cubes and dry them out overnight on a baking sheet. (If you are in a time crunch, you can quickly toast the sandwich bread cubes on a large baking sheet in the oven).

Preheat Oven: The next day, heat your oven to 400°F (200°C).

Crumble and Combine: Crumble the dried cornbread into little bits. Combine the crumbled cornbread, sandwich bread cubes, salt, black pepper, dried sage, finely diced onions, and finely diced celery in an extra-large mixing bowl. Toss everything together to mix thoroughly.

Hydrate the Bread: Add five cups of the chicken broth to the bowl and stir to combine. Crucial Step: Taste the mixture now and adjust your seasonings (salt, pepper, sage) if needed before adding the raw eggs.

Add the Eggs: Whisk the 6 eggs lightly and stir them into the cornbread mixture. The cornbread mixture should be very wet and soupy in consistency. Add the additional 6th cup of chicken broth if the mixture looks too dry.

Prep the Pan: Pour the wet mixture into a well-greased, 10 x 15 inch casserole dish and spread it out evenly in the pan.

Bake Covered: Cover the baking dish tightly with aluminum foil. Bake at 400°F for exactly 1 hour.

Test and Finish: After the elapsed time, uncover the casserole and gently shake the dish. If the center jiggles heavily, it is not done. If it is firm to the touch, it is done. If it doesn't look fully set, leave it uncovered and bake for additional time until it is firm but still moist on the inside. (This could take 5-20 minutes more depending on how deep your specific casserole dish is or how dry your bread was in the beginning).