dried wild mushrooms,
olive oil,
unsalted butter, plus more for greasing the pan,
mixed fresh mushrooms, such as cremini or shiitake, trimmed and sliced ¼-inch thick,
large (or 12 medium) fresh sage leaves, thinly sliced, plus more for garnish, if desired,
small shallots, halved and thinly sliced,
cognac (optional),
kosher salt, plus more to taste,
Black pepper,
medium leeks (340 grams or 12 oz), white and pale green parts only, halved lengthwise, thinly sliced and well washed,
large eggs,
heavy cream