The Food and Drug Administration (FDA) has launched an investigation into Taylor Farms, a supplier for McDonald’s Corporation (NYSE:MCD), after multiple people fell ill with E. coli linked to the restaurant chain’s Quarter Pounder. What Happened: According to an NBC News report, Taylor Farms has recalled four of its onion products, citing “potential E. coli contamination.” The company reportedly sent out a notice asking customers to get rid of the affected products. The FDA is investigating the McDonald’s supplier and currently believes slivered onions served on McDonald’s hamburgers are the m…