Approach:  Descent to the Ponteilles valley

(Blue line on the photo).
From the top of the Chaz Dura lift 2579m go down the piste towards Arnouvaz to reach the Ponteilles valley at around 2100m.

Route

Put on the skins. Go SW, up the Ponteilles valley, keeping mainly to the true right bank, (left side going up,) to avoid little outcrops.  Around 2170m go up a steep slope to the left to reach the upper part of the valley, under the summit of Mont Valaisan. Go up to the Grand Glacier col (France-Italy border.)  From the col reach the summit, firstly by the narrow S ridge then a SE facing cwm.  

Descent

By the same route to the start of the climbing, then continue down the centre of the valley.  At about 2050m keep to the true left bank of the river and descend to la Joux, through the clearings and by a broad track.  From La Joux, after a short uphill section, reach the foot of the Thuile ski network.