Unpacked a yeast concoction just before Lent (7,7)

I believe the answer is:

pancake tuesday

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'before lent' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.

'unpacked a yeast concoction' is the wordplay.
'concoction' indicates an anagram.
'unpacked'+'a'+'yeast'='unpackedayeast'
'unpackedayeast' anagrammed gives 'PANCAKE TUESDAY'.

'just' is the link.

Can you help me to learn more?

I've seen this clue in The Daily Express.

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