Ok I found it. In your report Try this:
[Sales:5, 2, 2,1]
@{REPORT ORDER DETAILS:O.MenuItemName,O.ExactTotal.Sum.desc:(ODI=True):{0}:,}
>{REPORT ORDER DETAILS:O.MenuItemName,=[O.Quantity.Sum.desc],O.ExactTotal.Sum.desc:(ODI=True) and O.MenuItemName="$1"}
{REPORT ORDER DETAILS:' '+[O.PortionName],=[O.Quantity.Sum.desc],O.ExactTotal.Sum.desc:(ODI=True) and O.MenuItemName="$1":2}