1. Preheat oven to 375F. 2. Melt the butter in a small pan. Add onions, and saute over medium heat for a few minutes. When they begin to soften, add mushrooms, salt, pepper, thyme, and mustard. Saute about 5 minutes more and remove from heat. 3. Combine eggs, milk, and flour in a blender or food processor, and beat well. 4. Spread the grated cheese over the bottom of the unbaked crust, and spread the onion-mushroom mixture on top. Pour in the custard, and sprinkle top with paprika. 5. Bake for 35-45 minutes, or until solid in the center. Serve hot, warm, or at room temperature. ~--