n Punta Indren, cross the glacier towards the rocky section. Ski along the rocks and then hike upwards 10 minutes (a rope can be useful) to the top of the col from which the narrow and steep gorge starts.
Ski all the way down, pass the moraine and cross the glacier (watch out for the crevasses). Keep high to avoid the big jump and traverse the wide plateau towards Bettaforca. Follow the wood until you find the municipal water system (a cement block) and then take the right heading the Bettaforca ski run that takes you directly down to Staffal.
You might need topo maps, harness, ropes and big mountaineering experience.