A big day out, with a few options for some classic couloirs off the Crête du Lauzas, can be combined with a lift assisted run down the Montagnolle.
Starting at the Monêtier les Bains ski station, you follow the piste out towards the Grand Tabuc valley. The Piste that you follow is often closed or never very busy, but be aware that you could have skiers coming down. Follow the lift back up and over a bridge, a few hundred meters up turn off south west and follow a path that traverses above the river. Be aware that this is the path you ski back down from the classic Montagnolle run, it is narrow in places and you can get skiers coming down quite quick. Stay on the same bank for quite a while, you will pass a first bridge, ignore it and then as the valley starts to open out you can cross over the river. Follow the valley floor as it bends west and becomes very wide, you will see the Crête de Lauzas on your left, there are three or four couloirs along the Crête some of them quite steep and narrow. Before the valley starts to narrow again, turn north and climb to towards some broken ground with small couloirs that link up, they are south east facing (most of the other lines are south facing). Climb to the left of a big rock and then keep following the obvious line up. There is a point where the line splits, you can traverses the slope and climb a diagonal ramp to the summit, or climb straight up to a small col, the stats etc below are for the Col.
Ski down the the same line, there are a few options for heading out of the couloir and on to some of the faces but we did it in a low snow year and needed to be sure that the snow linked up. At the bottom of the valley ski down whichever side you want to get the best snow south or north facing. Make sure you are on skiers right as the valley narrows as this is the path back to the piste. Follow the piste back to the resort.