Not sure if these are the same type of fungus as shown in Heino's sighting 4571293. Assumed to be Truffles. They haven't changed size or shape appreciably over the past week.
In an earlier comment I noted that various truffles have white(ish) exteriors. Hence a view of such an exterior contains almost no information. I collected some specimens from the group Tim photographed and show a few of them here: https://canberra.naturemapr.org/sightings/4573249. For an internal view of the Austrogautieria referred to by Tim, see this sighting: https://canberra.naturemapr.org/sightings/4571293.