Preheat the oven to 300°F. Place the cubed bread on a rimmed baking sheet and drizzle with olive oil. Add a pinch of salt and toss to evenly combine. Bake, stirring every 10 minutes, for 30-35 minutes until dry and slightly toasted. Let cool.

In a skillet over medium-low heat, add the butter and melt. Add the onion, celery, and 1/4 teaspoon salt and cook until completely soft, about 15 minutes. Add the garlic, thyme, sage, pepper, 1/4 teaspoon salt, and gluten-free soy sauce (if using) and cook for another 1-2 minutes. Remove from heat and set aside.

To make-ahead, stop here and store the celery/onion mixture in the fridge until the next day and keep the toasted bread at room temperature.

Preheat the oven to 375°F. Heat the chicken stock in the microwave or in a skillet until just simmering. Place the eggs in a bowl and whisk to combine. Slowly add the hot stock to the eggs, starting with just a few tablespoons while whisking constantly. Add the rest of the stock while whisking.

Place the bread cubes, celery/onion mixture, and stock/egg mixture in a large bowl and gently stir to combine. Pour into a greased 9x13 baking dish and cover tightly with tin foil.

Bake covered for 30 minutes. Uncover and continue to bake for another 10-15 minutes until golden and toasted on top. Serve and enjoy!