In a nonstick skillet, heat the 2 tablespoons of olive oil. Add the mushrooms, season with salt and cook over moderately high heat, stirring occasionally, until softened and lightly browned, 12 minutes. Transfer the mushrooms to a work surface and let cool slightly, then coarsely chop. Transfer the mushrooms to a large bowl. Add the <em>panko</em>, cheese, parsley, basil, lemon juice and cayenne and season with salt. Add the eggs and egg whites and knead the mixture to combine.