Preheat oven to 325 degrees (165 degrees C)
Grease a 3 quart baking dish
Cut bread into cubes about 3⁄4 inch square and spread onto a baking sheet
Bake in a preheated oven until crisp, 12 to 17 min
Heat olive oil in a large skillet over medium heat. Cook and stir onions, celery, sausage in the hot oil until soft, 8 to 10 minutes. Stir sage, thyme, salt, and black pepper into the vegetables. Mix toasted bread crumbs, chicken broth, mushrooms and eggs into vegetables. Spoon dressing into the prepared baking dish and cover dish.
Bake in the preheated oven for 30 minutes, uncover, and bake until the top of dressing is crisp and lightly browned, about 10 more minutes.