Preheat the oven to 400 degrees F (200 degrees C).
Brown the Spicy Italian Ground Sausage (8 ounce) on medium/high heat. Drain and remove from pan. Set the browned sausage aside and leave the pork fat in the pan for later use.
Slice the Shallot (1). Roughly chop the Wild Mushrooms (2 cup). Chop the Garlic (2 clove) and Fresh Rosemary (1/2 tablespoon).
Cut the Rustic Bread (4 cup) and Gouda (6 ounce) into cubes and set aside.
Heat the same pan you browned the sausage in over medium heat, add Butter (3 tablespoon) and saute the shallots, garlic, rosemary, and mushrooms together until fragrant and softened. Add sausage. Remove from heat.
In a large bowl, whisk together the Egg (5) and Milk (2 cup).
Add the cubed bread, along with the mushroom mixture.
Add torn Escarole Lettuce (3 cup) to the bowl, along with the cubed gouda and fold everything together.
Butter your baking dish.
Pour the mixture in to the baking dish and season with Salt and Pepper (to taste).
Bake uncovered for 25 minutes.