Dried porcini give an earthy, punch to this Italian classic. Although it tastes great hot from the oven, the fennel-and-mushroom combination mellows beautifully overnight.
Make Ahead Tip: Bake, let cool for 1 hour, cover with foil and refrigerate for up to 3 days. Reheat, covered, in a preheated 350 degrees F oven for 45 minutes.