At Vatoped Monastery from the Holy Mountain are kept several pieces from the Holy Cross on which our Lord Jesus Christ was crucified.
Every year on the day of the Elevation of the Holy Cross a cross having embedded in it one of these pieces from the wood of the Holy Cross is taken out of the altar.
After being worshiped at the end of the vigil under the Holy Cross it is placed a mixture made of water and flour. This lifeless mixture is made alive by the Holy Cross and at the end of the Liturgy is alreadu turned into leaven which grows and it is used by the monks of the monastery for making bread and antidora until the next feast of the Holy Cross.
Thus the bread and antidora are made at Vatoped without yeast.
Source: http://doxologia.ro
A similar miracle takes place every year at Dionisiu Monastery.
During the feast of the elevation of the Holy Cross after doxology the priest keeps in his hands the Holy Cross and comes out on the northern deacon`s door after the sextons who carry burning candles.
In the year 1959, at Dionisiu Monastery from the Holy Mountain after it was pronounced the first litany from the traditional service of the Elevation of the Holy Cross which takes place in the middle of the Church while the priest was going to the other side of the altar to say the second litany the baker of the monastery, father Arsenios approached him keeping in his hands a vessel with a little bit of dough made of flour and water which he put under the disk with the Holy Cross.
Seeing this one of the elders with whom I was staying in the right side pew got upset and told me in a whisper:
`Father Lazarus what is this fool doing ? Why does he bother the service?`
`He forgot to put the dough at the due time and that is why he tries to put it now under the Holy Cross. He should have put it at its time without bothering but even now the grace of the Holy Cross will work so that the dough may turn into new leaven.
This is a miracle which has been taking place every year for ages but only a few know it.
Finding out these the old man who despised father Arsenios remained stunned and he marveled at the miracle made by the Holy Cross. Afterwards he was told about this miracle by other monks and especially by the monk who made the antidora in the monastery, father Sophrony who confessed that when he put for the first time the dough under the Holy Cross he felt a great mistrust and doubted that any leaven would come out.
`But what a strange miracle` father, that one said, to my complete conviction in the same day after the Holy Liturgy was ended I went to the room where I was making the antidora and where I had put the dough and I uncovered very doubtfully the vessel and I saw that it was grown up and it flew over the brims. Then I marveled I made the sign of the cross and glorified God asking Him to forgive me for my former disbelief.
This happened purposefully for my disbelief because as the monks who knew what usually happens told me, in the first day it grows only a little. Then they knead it with new flour and the next day grows so much that it pours over the brims.
I mentioned this miracle, although it is known by many, as there have always been people like Thomas the unbeliever but also for being known by the future generations whose faith only God knows how ardent will be.
Excerpt from Stories from Dionisiou – Monk Lazarus from Dionisiou, Evanghelismos Publishing.