The White Button (Agaricus Brunnescens) is the most frequently used of all Mushrooms. Also, called "Champignon", they've been cultivated by the French since the 1700's. Today, the United States is the largest grower of cultivated White Button Mushrooms. The "Champignon" has a mild flavor.
There is no preparation needed. Mushroom powder is ready to use, just add to your recipe.
Ground Champignon Mushrooms