Heat a non-stick skillet over medium-high heat. When hot, add the mushrooms and the water. Cook the mushrooms in the water for 1-2 minutes, until just starting to wilt, but not completely softened. Chestnut mushrooms will take 2 minutes. Thinner, more delicate mushrooms will only take 1 minute. Do not overcook the mushrooms.
Add in the butter, and saute the mushrooms until just tender. Turn the heat to medium. Add in the egg/creme fraiche mixture. Use a spatula to gently scramble the eggs. The eggs should cook slowly to retain their silky, light texture. Cook until just set. Sprinkle with shredded cheese. Season with salt, pepper and fresh parsley. Drizzle with hot sauce, if desired.