This umbellifer has 3-pinnate lower leaves, purple/ purple spotted stems which are broader at the nodes and hairy. About 50cm - 80cm high.
No interactions present.
The fruits look just like the ones in Rose for Rough Chervil.
Lat/Lng: 51.5513, -1.2108
OS grid ref: SU548838
Growing in shade of a hedgrow in calcareous grass alongside (e.g.) Knapweed and Pyramidal Orchids