What is this delta-winged aircraft?
Took a fair bit of trial and error on the very vague registration on the port wing :)

F-PDHV (D-Plane 1)


  The Verhees D-Plane 1 is a Belgian homebuilt flying wing,
  designed by Verhees Engineering and supplied as plans for amateur
  construction.


Picture from below:



Source



David Osborne/ Aeroprints Source