One way to get salt when all else fails (4,6)
I believe the answer is:
'one way' is the definition.
(last resort is a kind of way)
'salt when all else fails' is the wordplay.
I cannot quite see how this works, but
an anagram of 'salt' is 'last' which is located in the answer.
'when' could be 'e' (I've seen this in other clues) and 'e' is present in the answer.
This may be the basis of clue (or it may be nonsense).
'to get' is the link.
Can you help me to learn more?
(Other definitions for last resort that I've seen before include "when everything else has failed?", "When all else fails, try this", "Final expedient".)