Can you describe the miracle Sai Baba performed for Boss Dharamsee involving grapes?

Certainly. The story, detailed in Chapter 35, recounts when a devotee named Kaka brought grapes with seeds as an offering to Sai Baba. He was accompanied by his skeptical boss, Dharamsee, who disliked seeded grapes. Baba, knowing this, began distributing the grapes and gave some to Dharamsee. Troubled, Dharamsee initially hesitated but eventually ate them as commanded by Baba. To his great surprise, he found the grapes were entirely seedless. This experience was unique to him, as another devotee, Babasaheb Tarkhad, confirmed that the grapes he received from Baba at the same time did have seeds. This miracle stunned Dharamsee, causing his skepticism and ego to dissolve.