Could this be Peziza cerea? Substratum is strange. For P. varia paraphyses do not fit. For other Peziza of similar color (which I was able to find descriptions) spores seem do not fit.

Habitat: mixed wood edge; mountain trail side with Fagus sylvatica, Ostrya carpinifolia and Fraxinus ornus in the vicinity; rocky place, slightly inclined mountain slope, east aspect; in shade; relatively warm place; calcareous, skeletal ground; partly protected from direct rain by tree canopy; average precipitations ~ 3.000 mm/year, average temperature 7-9 deg C, elevation 585 m, alpine phytogeographical region.

Substratum: on moss covered solid limestone rock with a thin layer of humus beneath the moss (mass can easily be 'peeled off' the rock). No buried wood found in the vicinity except eventually some very thin roots less than 1 mm thick.

Place; Lower Trenta valley, between villages So?a and Trenta, near Skokar farm house (Trenta 2); East Julian Alps; Poso?je, Slovenia EC. Lat: 46,360270, Long: 13,703867, elevation 585 m.

Spores: (14.2) 14.5 - 15.9 (16.3) × (7) 7.3 - 8 (8.2) µm; Q = (1.8) 1.9 - 2.2 (2.3); N = 28; Me = 15.2 × 7.6 µm; Qe = 2. Some spores seem to be very slightly punctuated (not visible on the spore picture). When observed slightly out of focus they show two oil drops.
Asci: (239.7) 242.8 - 296.7 (298.1) × (11.5) 13.7 - 16.6 (20.2) µm; Q = (11.9) 14.6 - 21.7 (23.5); N = 14; Me = 269.2 × 14.7 µm; Qe = 18.7.
Paraphyses: diameter: (3.9) 3.93 - 4.7 (5) µm; Me = 4.3 µm; diameter at the tip: (5.5) 6 - 7.3 (7.9); Me = 6.6 µm.

Growing solitary. Sporocarp's dimensions: 4 x 3.5 cm, h = 3 cm; in the field inner and outer surface nearly of the same color, after 2 days in half dry state inner surface darker, reddish-brown and outer side lighter, whitish-grayish; hymenium near the edge consisted of almost only paraphyses with some not yet mature asci and in the center of the sporocarp almost only asci with few paraphyses; taste indistinctive, mildly mushroomy; smell: almost none, lightly on earth, rotten leaves??

Many thanks for your time and help.

Sincerely
Amadej Trnkoczy