In a small saucepan, combine dried porcinis with Madeira, and bring to a boil. Remove from heat and allow to sit for 20 minutes, or until mushrooms are very soft and liquid is flavorful. Strain mushrooms and broth through a fine sieve or coffee filter and reserve liquid. Rinse mushroom pieces under running water to remove any residual dirt or sand, then roughly chop porcinis and reserve.

In a soup pot or saucepan heat butter and saute onions, leek and garlic until vegetables are soft and lightly caramelized, about 6 minutes. Add mushrooms and continue to cook until they have released their liquid and most liquid has evaporated, about 4 minutes. Sprinkle flour over mushrooms and vegetables, stir to mix well and cook for 2 minutes. Add reserved porcini liquid, chicken stock, thyme, and reserved porcinis and bring to a boil. Reduce heat to a simmer and cook for 45 minutes. Add heavy cream and cook for 15 minutes. In a blender puree the soup in batches and return the pureed soup to the pot to keep warm until ready to serve. Taste and adjust seasoning, if necessary, and serve in bowls, each bowl garnished with 1 halved quail egg.