Underneath the soil on the cap is a white remnant of the universal veil (a membrane that wrapped the entire mushroom when it was still in the unexpanded button stage). That suggests Amanita or Volvopluteus. The gills seem to be naturally non-white rather than that colpour being an artefact of the lighting and Volvopluteus has pale pinkish-brown gills - hence my choice of that genus and size then makes me choose Volvopluteus gloiocephalus.