Master Recipe 
I call this crowd-pleasing soup my magic recipe. It is so amazing that so few ingredients—and a soup made in a matter of minutes—can have so much depth of flavor. It really is a fine example of the miracles of infusion. The dried cèpe (porcini) mushroom powder packs a maximum of fragrance and flavor and takes well to many variations: pair it with paper-thin slices of raw domestic mushrooms or seared domestic or wild mushrooms showered in the bowl at serving time; prepare with dried morel powder in place of cèpes; top with thin slices of raw black truffles; or add a dollop of mushroom-powder-infused whipped cream.
8 SERVINGS
EQUIPMENT: A large jar with a lid; a 3-quart (3 l) heavy-duty saucepan with a lid; 8 warmed, shallow soup bowls.
2 cups (500 ml) heavy cream
2 tablespoons Cèpe Mushroom Powder
1/2 teaspoon fine sea salt
3 cups (750 ml) Chicken Stock or Vegetable Stock
Chopped fresh chives, for garnish
Extra-virgin olive oil or Chive Oil, for garnish
1. If time permits, combine the cream and mushroom powder in a jar, seal, and refrigerate for 24 hours to infuse the cream with the mushroom flavor and aroma. (Alternatively, combine the cream and mushroom powder in the heavy-duty saucepan, bring just to a simmer, cover, remove from the heat, and set aside for 30 minutes to infuse the cream.)
2. At serving time, in heavy-duty saucepan, combine the infused cream, salt, and stock and bring to a gentle simmer over medium heat. Remove from the heat and taste for seasoning.
3. Serve in the warmed soup bowls, garnished with chives and a drizzle of oil.
VARIATIONS: Add sliced raw domestic or wild mushrooms to the soup and cook for several minutes; add grilled, sliced fresh cèpes or domestic mushrooms; add truffle matchsticks at serving time.
MAKE-AHEAD NOTE: The soup can be prepared up to 3 days in advance and stored in airtight containers in the refrigerator.