Could you detail the miracle involving Boss Dharamsee and the grapes at Shirdi?

Certainly. As recounted 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 visiting with a skeptical attitude. Dharamsee disliked grapes with seeds and was also concerned about eating them unwashed. He mentally challenged Baba, wondering why a true saint would force something on him that he disliked. Baba then gave him even more. When Baba commanded, 'Throw them in and eat,' Dharamsee obeyed. To his astonishment, the grapes he put in his mouth were completely seedless. He later confirmed with another devotee, Tarkhad, that the grapes given to him did indeed have seeds, highlighting the personal and miraculous nature of his experience.