Exotic fruit (The Rings of Akhaten)

What the Eleventh Doctor called "exotic fruits of some description" were fruits found at a market on Tiaanamat. They were found in baskets, and resembled glowing blue balls. They were non-hallucinogenic, high in free radicals, and according to the Doctor, low in "other stuff, I shouldn't wonder."

When the Doctor and Clara Oswald visited Tiaanamat for the Festival of Offerings, Clara tried one and didn't like it. (TV: The Rings of Akhaten)