Preheat oven to 325 degrees F. Butter a 9x13 baking dish. Place stuffing cubes in a large mixing bowl. Set aside.
Melt 2 tablespoons butter in a large skillet over medium heat. Add sausage to the skillet. And cook until browned, 5 minutes. Remove from pan and let cool.
Melt 2 more tablespoons butter in the same skillet and add the onions, mushrooms, and celery. Cook until onions are softened and garlic is fragrant, about 5 minutes.
Add the sausage, onions, garlic, celery, and any pan drippings into the bowl with bread cubes.
Add broth, parsley, sage, thyme, salt, and pepper to the mixing bowl. Gently stir everything together until moistened.
Mix in the walnuts and eggs until combined.
Pour the dressing into your prepared pan and spread into an even layer. Don’t pack it down too much.
Bake for 30 minutes uncovered until a crust form on the top. Drizzle 2 tablespoons melted butter over the top of the stuffing. Cook until the top is crisp and golden, about 15-20 minutes more.
Remove from oven and serve warm.
Notes
To toast the walnuts: Spread them on a baking sheet and toast at 250 for 7 minutes until golden. Do this while you cook the sausage and veggies. Then turn the oven heat down.
Instead of pre-made stuffing cubes, you can use 1 pound of 2-day old French bread. Cut it into bite-sized pieces and proceed as directed.
If you haven't let the bread dry out, cook the bread cubes on cookie sheets for 10-12 minutes at 375 degrees.