The choices: "Healthy Japanese, a light Japanese meal; Bella Italia, featuring popular Italian dishes; an Indonesian rice table, featuring various traditional dishes and an exclusive vegetarian meal."
The cost? Oh, just 12-15 Euro ($17-21) extra, a small price to pay if you suffer from food allergies or are just a picky eater. Just be sure to order your special meal (which you can indicate online when you book or manage your booking) between 90 days and 48 hours before your flight to make sure they stock it onboard for you.
Bonus news! The special meals concept will soon be expanded to KLM Business Class as well, where five other selections will be offered for order and provided complimentary on flights to Cape Town and Singapore, assuming you indicate your choice early.