Could you recount the miracle of the seedless grapes that happened to Boss Dharamsee?

Certainly. As recounted in Chapter 35, a devotee named Kaka brought grapes with seeds as an offering to Sai Baba. Baba began distributing them, including to a visitor named Boss Dharamsee, who was skeptical and disliked that variety. Troubled, Dharamsee ate one and hid the seeds. When Baba offered more, Dharamsee hesitated, but Baba insisted he eat them. When Dharamsee put this second handful into his mouth, he was shocked to find they were all seedless. His amazement grew when another devotee, Tarkhad, confirmed that the grapes he received from the same bunch did have seeds. This personal miracle convinced Dharamsee of Baba's divine power, and his skepticism transformed into deep love and faith.