With stock tracking (Base plan or higher, or the Ingredients Stock module) the list shows the ingredient's Stock on hand for the active kitchen and Total Needed = trimmed quantity − stock (with its conversion underneath). Only ingredients whose Total Needed is above zero are put on supplier emails.

You can correct stock without leaving the report: with a kitchen selected, click the stock value and type the new quantity (Enter the quantity in stock); in Global View, click it to open the Edit Stock modal with one row per kitchen and press Submit.