Cook prepared tart mix, printing method (3,6)

I believe the answer is:

dot matrix

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'printing method' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.

'cook prepared tart mix' is the wordplay.
'cook' becomes 'do' (do can mean to cook).
'prepared' indicates anagramming the letters.
'tart'+'mix'='tartmix'
'tartmix' with letters rearranged gives 'tmatrix'.
'do'+'tmatrix'='DOT-MATRIX'

Can you help me to learn more?

(Another definition for dot matrix that I've seen is " type of printer".)

I've seen this clue in The Independent.

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