I had never eaten porcini mushrooms before 1995. That winter, we went on a vacation and stayed in the Florence suburb of Fiesole.There was a restaurant not too far from the guest house that we went to for dinner one evening. The restaurant served all kinds of Italian food, but we decided to have just a pizza garnished with fresh porcini mushrooms. They were in season and nothing taste as good as fresh saute porcini. We ordered one pizza with porcini on it. We were with my husband's cousin and her husband, so we intended to split the pizza four ways.We ate the pizza, but its taste actually was stunning. None of us had ever eaten anything that good before, and even though we thought we weren't very hungry, we ordered another, until our intake totaled seven pizzas.Mushrooms were used by the ancient Greeks and Romans. The Roman emperor Claudius actually was murdered by his wife, Agrippina, who slipped a couple of poisonous mushrooms into a dish of his favorite edible mushrooms.The Romans were able to cultivate several kinds of mushrooms, but cultivation on a large scale really began in the 17th century, when a French botanist discovered how to grow them in compost year-round. The white mushrooms that are found in American supermarkets are descendants of what the French call champignons de Paris. Paris had the best circumstances for mushroom cultivation-huge quarry caves around the city which, when the quarries were played out, were given to gardeners who created a substantial mushroom industry. In the 18th century, Chinese and Japanese botanists cultivated the famous shiitake and straw mushrooms, using French techniques. It was American botanists who learned on their own, despite French refusal to give up their secrets, how to cultivate what we now call"button" mushrooms, which is what we buy in stores today.There are dozens of varieties of edible mushrooms, including portobello and shiitakes, which some people use in place of meat because of their meaty texture.Never store mushrooms in a plastic bag, as they will sweat and turn mushy. Keep them in a paper bag, and store them for no more than two days in the vegetable compartment of your refrigerator. One should never wash mushrooms with water but instead, clean them with a soft brush of wipe them clean with a paper towel.Re-moisturize dried mushrooms by soaking in hot water for about 20 minutes, then drain and use as though they were fresh. Keep the soaking water and use it in stocks or sauces, giving the dish you use them in an intense mushrooms flavor.Baked potato casserole with mushrooms toppingserves 4-62 large russet potatoes1/4 teaspoon paprika6 tablespoons olive oil1 pound fresh white mushrooms, thinly sliced1 medium red onion, julienned1/2 cup sun-dried tomatoes2 cloves garlic, mashed1 teaspoon ground coriander1 large ripe tomato, diced4 tablespoons chopped fresh cilantrosalt and pepper to taste-Peel and cut the potatoes into 1-inch cubes. Place two tablespoons of olive oil in a bowl with the paprika. Add the potatoes and toss until well coated. Place the potatoes in a deep baking pan. Bake in a 400 degree F. oven. for 25 minutes.-In heavy saucepan, heat the rest of the olive oil. Add the mushrooms and cook over medium-high heat. Stir and continue to cook until the water is evaporated.-Add the onion to the mushrooms, stir and cook for couple of minutes.-Add the sun-dried tomatoes, the garlic, the coriander, the ripe tomatoes and the seasoning. Stir and cook for 5 minutes.-Take the potatoes out of the oven, pour the mushroom sauce over the potatoes, sprinkle with the fresh cilantro and serve.