Cauldron heartens witch, but takes a long time to make stew (7)
I believe the answer is:
pottage
'stew' is the definition.
(I know that pottage is a type of stew)
'cauldron heartens witch but takes a long time' is the wordplay.
'cauldron' becomes 'pot' (I've seen this in another clue).
'heartens witch but' becomes 't' (I can't explain this - if you can you should believe this answer much more).
'takes' means one lot of letters go next to another.
'a long time' becomes 'age' (an age is a period of time).
'pot'+'t'+'age'='POTTAGE'
'to make' is the link.
Can you help me to learn more?
(Another definition for pottage that I've seen is " Soup or stew".)