According to this description on the menu, it is not sushi, but a selection of fruits and pastries:
http://www.themouseforless.com/tripplanning/menus/wdw/StarringRoll.shtml
On the easywdw site there's a (hard to see) photo and a comment following the article in which someone says it can be purchased with a CS credit, but it counted as the entree and dessert:
http://www.easywdw.com/dining/starring-rolls-cafe/
We've ordered a sandwich, cupcake (Butterfinger or the peanut butter and chocolate cupcake) and beverage with a CS credit.