Cut the bread into large cubes and spread them onto a baking sheet. Leave them uncovered overnight to get stale.
Preheat the oven to 350 degrees F. Grease a 9-by-13-inch baking dish with 1 tablespoon of the butter.
Put a large skillet over medium heat and add the remaining 2 tablespoons butter. When it is melted, add the mushrooms, celery and onions and season with salt and pepper. Cook until all the vegetables have softened, 6 to 8 minutes. Let cool for a few minutes.
In a large bowl, combine the bread, cooked vegetables and water chestnuts. Toss to combine. In a separate bowl, whisk the eggs with the broth, parsley, soy sauce and citrus juices. Fold into the bread mixture. Sprinkle with salt and pepper. If the mixture seems too dry, add more broth or a little water. Spread the mixture into the prepared baking dish. Can be covered and refrigerated overnight until you are ready to bake. Let it come to room temperature first.
Cover the pan with foil and put it into the oven for 20 to 25 minutes. Uncover and cook until the top is browned, about another 20 minutes. Let rest for 5 minutes before serving. Reserve 1 cup for another use if desired, such as the Round 2 Recipe Thanksgiving Pie.