Climber untested: a recipe for disaster on Eiger's flanks (8,7)
I believe the answer is:
virginia creeper
'climber' is the definition.
(I've seen this before)
'untested a recipe for disaster on eiger's flanks' is the wordplay.
I cannot really see how this works, but
'a' could be 'per' (eg 'one a day' means 'one per day') and 'per' is found within the answer.
'recipe' could be 'r' (abbreviation) and 'r' is located in the answer.
'on' could be 're' ('on' can be mean 'with reference to') and 're' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for virginia creeper that I've seen before include "going up the wall!" , "plant" , "Climber" .)