Preheat oven to 350°. Grease a 2-quart baking dish and set aside.
Cut or tear bread into 1-inch cubes and spread out evenly on a large baking sheet, or 2 baking sheets. Toast the bread in the oven until completely dry about 20 minutes, transfer to a large mixing bowl.
In a large skillet over medium heat, add olive oil and mushrooms. Saute, stirring occasionally, until golden brown (about 5-7 minutes). Add onion, celery, and fennel to the pan, saute for 2-3 minutes. Add 3/4 of the fresh herb mixture; thyme, sage, and rosemary, (reserving about 1 tsp for the top of the stuffing) continue to stir adding salt and pepper. Add 1/4 cup vegetable stock to the pan and continue to stir and cook until vegetables have softened, about 5 more minutes.
In a medium bowl whisk 2 eggs until well scrambled, add remaining vegetable broth.
Combine vegetable mixture with toasted bread cubes and pour the vegetable broth and egg mixture over the bread and toss to combine until the bread cubes absorb the liquid. Pour the mixture into the greased baking dish, sprinkle the top with reserved fresh herbs. Bake in the center of the oven until the top is golden brown, about 40 minutes. Remove the stuffing from the oven and allow to cool for at least 15 minutes before serving.
MAKE AHEAD:You can make this stuffing up to 2 days in advance. Store covered in the refrigerator and heat in the oven (350°) until warmed through (about 20 minutes) prior to serving.