On a paper-lined baking sheet, dry the torn bread pieces at a low temperature in the oven until just “stale.” Remove from the oven and increase the temperature to 400 degrees F. Leave shallots in the skins and roast for 20 minutes. Remove from the oven and cool. Remove from the skins and dice. Decrease the oven to 350 degrees F.
Meanwhile, place dried porcini in a non-reactive bowl. Bring 1½ cups seasoned water to a bare simmer and pour over porcini. Cover with plastic to rehydrate. Remove porcini and reserve, leaving remaining sand in bowl. Strain the liquid through a coffee filter and reserve. Repeat this process with the dried cloud ears. Once cloud ears are reconstituted, trim off the inedible stems.
In a medium pan, melt 2 Tbsp butter, add pancetta and render over medium-low to medium heat. Cook until crispy, about 5 minutes per side. Place the cooked pancetta on a paper towel lined plate and reserve.
Melt the remaining butter over medium-low heat. Add onion, shallots, celery, garlic, thyme and rosemary, and cover. Stir occasionally until the onions are translucent and soft but have not started to brown (about 5 minutes). Remove cover and add wine and reconstituted mushrooms. Cook until fragrant. Add the raw mushrooms and sauté until tender. Add remaining garnish and cool.
Transfer the onion mixture to a large bowl with the pancetta. Add the breads and eggs and combine. If needed, moisten with reserved mushroom liquid. Place in buttered 9×13 dish and cover with foil. Place in the oven and bake for 30 minutes. Remove the foil and bake for an additional 10-20 minutes until the top is golden brown. Remove from the oven and serve.