Enjoy fancy fungi and save money at the same time.
We typically soak dried mushrooms in hot water until they are just soft enough to chop, knowing that they'll continue to rehydrate when stirred into a sauce or soup. But dried mushrooms can also be used as a thrifty alternative to costlier fresh varieties in stir-fries or as toppings for pasta, pizza, or salads; in those cases they should be fully softened before being added to the dish. Here’s the best way to rehydrate five common varieties: porcini, morel, black trumpet, chanterelle, and shiitake. (Note: Even when fully rehydrated, the mushrooms will be slightly chewier than fresh mushrooms and won’t have exactly the same spectrum of flavors.)
Add water and dried mushrooms (1 cup of water per every ½ ounce of mushrooms) to a saucepan that can hold the mushrooms snugly and keep them submerged. Bring to a boil over high heat, cover, reduce the heat to medium-low, and simmer until the mushrooms are tender, 15 to 30 minutes. Remove the mushrooms. Strain the cooking liquid through a fine-mesh strainer to remove the grit; reserve the liquid for another use. (Discard the cooking liquid from black trumpet mushrooms; it is unpleasantly bitter.) Squeeze the mushrooms to eliminate any excess moisture. For use as a topping, sauté them in oil until hot and season them with salt and pepper.