Begin by baking 16 Southern-style cornbread muffins and 8 biscuits, either from scratch or using Bisquick, up to 2 days before you're ready to make the dressing. Allow them to cool completely, then cut them into small cubes.

In a medium saucepan, combine 5 cups of chicken stock, 1 cup of finely chopped celery, and 1 medium finely diced onion. Bring the mixture to a gentle simmer over medium heat, stirring occasionally. Cook for about 10 minutes, or until the vegetables are tender and fragrant.

In a large mixing bowl, crumble the prepared cornbread and biscuits together until they form a coarse texture. Gradually pour in the vegetable and broth mixture, about 1 cup at a time, stirring to integrate thoroughly.

Sprinkle in 1 tablespoon of poultry seasoning and ½ teaspoon of salt, adjusting to your taste preference. Mix everything well, ensuring the seasoning is evenly distributed throughout the dressing.

Incorporate 4 beaten eggs into the bread mixture, stirring thoroughly until everything is well combined.

Preheat your oven to 400°F (200°C). Grease a 9x13-inch casserole dish, then pour the prepared dressing mixture into the dish, spreading it evenly. Bake uncovered for 30-40 minutes, or until the edges are firm and the center is set.