A Quarter Pounder with cheese, fries and a drink arranged at a McDonald’s restaurant in El Sobrante, California, on Oct. 23, 2024. David Paul Morris | Bloomberg | Getty Images In the wake of last month’s E. coli outbreak tied to McDonald’s slivered onions, the fast-food giant said it will invest more than $100 million to boost restaurant sales and speed up the recovery at affected franchisees. Of that total,