Plate garnishes get recycled
"Most people don't eat the garnishes on the plate anyhow but I definitely wouldn't after seeing how many times a chef will grab a leaf of kale or whatever off an incoming plate and drop it onto one going out to customers. We have one dish that has a scoop of cottage cheese on the side. If it doesn't look touched, the chef will just slide it onto the next plate, or at the end of the night, right back into the container." —Ashton L.
13 Things Servers Won't Eat at Their Own Restaurants, Source:https://www.rd.com/list/things-servers-wont-eat-at-their-own-restaurants/