We wanted a cheese soufflé with bold cheese flavor, good stature, a light, but not-too-airy texture, without the fussiness of most recipes. To bump up the cheese flavor without weighing it down, we added light-but-potent Parmesan cheese to the Gruyère. To get the texture just right while keeping the preparation simple, we beat the egg whites to stiff peaks, and then—rather than carefully folding them into the cheese-bechamel—just add the sauce right to the mixer, and beat everything until…