Go to the Menu Module.
Search by Menu Category.
Click Filter.
Search by chosen Menu Category.
Click Apply Filters.
Click Reorder Menus.
Use the arrows on the left to drag and drop Menus to fit the order as you want them to appear on the Online Ordering Site.
When finished, the new order will show up on the Online Ordering Site. Double check that they are in the order you want on the Online Ordering Site.