Soil Cup Tarzetta cupularis
This is a small (ca 10mm) fungus which occurs (mostly) as a solitary fruiting body. This year I have found it three times in compost in flower pots. This third one is unseasonably late but this is because it was in as heated greenhouse (minimum 15C).
It lacks the crystalline appearance of the first one, which was more mature.
Olympus EM-1 (manual mode), Olympus 4/3 x2 TC, Olympus 4/3 50mm f2 macro, f11 (first) then f14 ISO 800, twin flash hand-held.
The stereos are crosseye.