Yes, mount pictures, etc., and get something to eat (3,4)

I believe the answer is:

jam tart

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'etc and get something to eat' is the definition.
I don't know anything about this answer so I cannot judge whether this works.

'yes mount pictures' is the wordplay.
'yes' becomes 'ja' (I can't explain this - if you can you should give a lot more credence to this answer).
'mount' becomes 'mt'.
'pictures' becomes 'art'.
'ja'+'mt'+'art'='JAM TART'

Can you help me to learn more?

I've seen this clue in the Evening Standard.

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