Step 1: Preheat your oven to 350°F (175°C) and grease a 9×13 inch baking dish with butter or non-stick spray.
Step 2: In a very large mixing bowl, combine the crumbled cornbread and the torn white bread pieces. Mix them gently to distribute.
Step 3: In a large skillet, melt the 1/2 cup of butter over medium heat. Add the onions and celery and sauté for 8-10 minutes until they are soft and translucent.
Step 4: Pour the butter and vegetable mixture over the bread crumbs in the bowl. Add the sage, poultry seasoning, salt, and pepper.
Step 5: In a small bowl, whisk the eggs with 1 cup of the stock. Pour this over the bread mixture.
Step 6: Gradually add the remaining stock, 1 cup at a time, tossing gently with a large spoon. The mixture should be very moist but not ‘soupy’.
Step 7: Transfer the mixture to the prepared baking dish and spread it evenly. Do not pack it down too tightly.
Step 8: Bake for 40 to 50 minutes, or until the top is golden brown and the dressing is set in the middle.
Step 9: Allow the dressing to rest for 10 minutes before serving to let the flavors meld and the texture firm up.