"I have been to meeting to day-heard an Italien preach, one Mr. Jefferson brought from Italy to instruct him in planting a vineyard.  But he found the grape did not succeed well here, and from a Roman catholic vinedresser he had become a Methodist preacher.  Our ministers here are all of the most ordinary.  An eloquent preacher is rarely to be met with.   We have ripe pears and huckleberries in abundance."

Martha von Briesen, Ed., The Letters of Elijah Fletcher,  Charlottesville, University Press of Virginia. 1965, p. 85.

In 1964, Martha von Briesen asked Jim Bear, then Curator at Monticello, to identify the person who might have given the 1814 sermon. In a footnote, she quotes Bear as follows:

"This might have been a member of the Giannini familiar, of whom Antonio, Francis, and Nicholas are mentioned in the Jefferson correspondence and account books, Antonio [Anthony] as late as 1811, according to James A. Bear, Jr., curator of the Thomas Jefferson Memorial Foundation, Inc, in a letter dated Apr. 7, 1964. He did not know of one who might have become a Methodist minister, however, "During the years [1778] Jefferson hired several other men to work for him, the most important of whom was Antonio Giannini, a vigneron, brought over from Italy by [Philip] Mazzei, to work at Colle," a farm just below Monticello

Edwin Morris Betts, ed., Thomas Jefferson's Garden Book, Philadelphia, 1944, p. 81.