Ghengis Khan's Mongol army included Buddhists, Muslims, and Christians. Did it ever include any Jews?

Michael Burgan's History of the Mongols mentions their interaction with Persia and Judaism. For most of history, Islamic societies have been tolerant of Jewish and Christian practitioners, seeing them as fellow "people of the book." Burgan discusses the large Jewish minority in Persia, which conquered by the Mongols. Like you alluded to, he also goes into depth about how the Mongol army expanded by recruiting conquered peoples after their defeat. He talks about one Jew, Sad al-Daulat, who was an official in the Mongol government who enforced the law. Specifically, he wrote, "Mongols came into contact with Judaism through their conquest of Islamic lands. Jews had lived in such cities as Baghdad for generations, and sometimes held important positions. Jews [after the Mongol conversion to Islam] who converted to Islam had the greatest chance of success under the Islamic Empire, and later under the Mongols." I can't give you any specific examples of Jewish soldiers unfortunately, but there were certainly Jewish residents of the Mongol Empire, many of whom served in government. Given the Mongols' tolerance for different religions and tendency to incorporate conquered peoples into their army (especially Persians), once can probably assume Jews served in their army.

http://www.mysocialstudiesteacher.com/wiki/classroom/Empires/Mongols.pdf