Heat to 225°F. Spread the bread cubes on a large rimmed baking sheet. Bake until quite crisp, stirring every 30 minutes, about 90 minutes total. Meanwhile, prepare the remaining ingredients. While bread cubes are toasting, prepare your other ingredients.
Grease with butter an 11 x 7 or 5 quart large baking dish and set to the side.
Melt 6 tablespoons unsalted butter in a large pan on medium to high heat. Add in your diced celery, yellow onions, and pressed garlic. Frequently stir and cook until the veggies are super soft. Stir in thyme leaves and chopped sage for the last few minutes. Remove from heat.
Grab a bowl and pour in your stock, 2 large brown eggs, salt, and fresh cracked black pepper. Whisk to break yolks and combine.
Add half of the toasted bread cubes with half of your garlic and onion mixture to a very large mixing bowl and fold to combine. Add the second half of the toasted bread cubes with the last half of your garlic and onion mixture. Fold and combine all ingredients in the bowl. Your bread will start getting a bit soggy at this point, looking more like wet stuffing.
Melt the last 2 tablespoons of butter and add into the folded mixture. Stir until even.
Slowly add in your egg mixture to the very large mixing bowl folding in until even.
Scoop into the prepared baking dish, making an even layer.
Cover tightly with aluminum foil and refridgerate up to 24 hours OR bake immediately in the center of the oven, covered at 375°F for 30 minutes. The top should start turning golden brown and lightly crisping. Uncover to bake another 20 minutes. *Add additional 10-15 minutes if baking from the refridgerator.
Let sit for 10 minutes before serving.
