Can you share the story of Boss Dharamsee's first visit to Shirdi and the miracle of the grapes?

Certainly. The story is detailed in Chapter 35. A devotee named Kaka brought grapes with seeds as an offering to Sai Baba. When Baba began distributing them, he offered some to Boss Dharamsee, who was a first-time, skeptical visitor. Dharamsee disliked seeded grapes and was hesitant to eat them unwashed, thinking that a true saint should know his preference. Perceiving his thoughts, Baba gave him even more. Finally, Baba commanded him to eat the grapes. Upon obeying, Dharamsee was astonished to find they were perfectly seedless. He confirmed with another devotee, Tarkhad, that his own grapes did have seeds. This personal miracle transformed Dharamsee's doubt into firm determination and love for Sai.