The short answer is get the Form & Function compilation album, to start you off.
The long answer:
Imo you need to listen to all the six 12s on Photek records (collectively known as Form & Function)
From discogs...
PTK01 Studio Pressure Form & Function Vol. 1 (12")
PTK02 Studio Pressure Form & Function Vol. 2 (12")
PTK03 Studio Pressure The Physical / Touching Down ... Planet Photek (12")
PTK04 Studio Pressure The Water Margin / Fusion (12")
PTK05 Photek The Seven Samurai (12")
PTK06 Photek U.F.O. / Rings Around Saturn (12")
In particular the last release is peerless.
The difficulty with the Form and Function compilation CD I mention above is he only put about half of the original tracks on (Water Margin, Rings Around Saturn, UFO, Seven Samurai) - the remainder of the CD is mainly mediocre remixes and was a real wasted opportunity to grasp the gift of major label money and distribution while he had the chance. Except, perhaps, the track Knitevision, which is about as minimal as jungle ever got and is almost up there with his best...
You should also check Ni Ten Ichi Ryu 12" and his Razors Edge release (The Rain rmx/Still Life).
Apart from a couple of tracks, his LP Modus Operandi is a disapointment (and was at the time).
P.S I think Source Direct shit on Photek and I await the day someone can do their genius justice and put out a proper retrospective...