To reach it you’ll need to hike to the peak of the Rocher du Charvet from the the top of the Grand Pré chairlift, and then skate or walk along the top until you reach the entrance of the couloir– a good 45 minute slog.
It’s narrow, steep and long, and once you’re in there’s no way out. It is high and North facing, so the snow quality holds well. As you reach the bottom your legs will be on fire, but once you’re out of the couloir the rest of the ski down will take the pain away. This is where you’ll find the best snow in Val d’Isère, and you can still get fresh tracks long after a snowfall; you’ll ski down a slope which is shaded by the peak, sheltered from the wind, and accessible by only the best and craziest skiers, of which you are now.
High level skiing. If there is an avalanche you are trapped.