Hazrat Ateşbâz-ı Veli (Yûsuf bin İzzeddin/Şemseddin Yusuf) was the cook of Jalāl ad-Dīn Muhammad Rūmī (Mevlana/Rumi) and an influential figure in the Mevlevi Order. He died in 1285 AD (the Seljuk era) at the age of 100. His tomb is in Konya, Türkiye.
Not only the cook, Hz. Ateşbaz Veli was also Mevlana’s confidante. He traveled from Khorasan to Karaman and then to Konya with Mevlana's father, Bahaeddin Veled, serving him, Mevlana, and Mevlana’s son, Sultan Veled.
As for how Şemseddin was named Ateşbaz: one day there was no wood left in the stove at the dervish lodge. Mevlana instructed Şemseddin to put his feet in the stove, where the wood would be. Şemseddin put his feet there and flames began to rise from his feet. While staring at this marvel, Şemseddin questioned whether his feet would burn. Because of his doubt, his left toe began to burn.
When Mevlana heard of this, Şemseddin felt ashamed. Şemseddin cut off the burnt toe by placing his right foot on his left foot. After that day, Şemseddin became known as Ateşbaz: the one who plays with fire. The start of the whirling sema, when dervishes place their right toes on their left toes, harkens back to this story.
Mevlana prayed over Hz. Ateşbaz Veli, saying, "May those who take from your salt find serenity; may those who visit you heal. May their food increase but not be lacking, may it overflow but not spill.” Because of this, Hz. Ateşbaz Veli’s salt continues to be cultivated to present day (by mixing the original salt with more salt, and continuing the process.) The keeper of Hz. Ateşbaz Veli’s tomb provides this salt for visitors to take home, mix with their salt at home to cultivate for their own use. This is the salt I’ve brought back and mixed to make more.