Instructions Ken discovered inside garden ornaments (7)
I believe the answer is:
genomes
'instructions' is the definition.
I know nothing about this answer so I can't tell whether this works.
'ken discovered inside garden ornaments' is the wordplay.
'discovered' indicates the central letters (dis-covered - outer letters removed).
'inside' means one lot of letters goes inside another.
'garden ornaments' becomes 'gnomes' (I've seen this before).
The middle of 'ken' is 'e'.
'e' inserted inside 'gnomes' is 'GENOMES'.
Can you help me to learn more?
(Another definition for genomes that I've seen is " DNA sequences of organisms".)