Customary solids offering flavoursome ingredients

I believe the answer is:

stock-cubes

I'm a little stuck... Click here to teach me more about this clue!

'flavoursome ingredients' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.

'customary solids' is the wordplay.
'customary' becomes 'stock' (I can't explain this - if you can you should give a lot more credence to this answer).
'solids' becomes 'cubes' (cube is a kind of solid).
'stock'+'cubes'='STOCK-CUBES'

'offering' acts as a link.

Can you help me to learn more?

I've seen this clue in The Telegraph.

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