土豆你个马铃薯番茄你个西红柿
[tŭ dòu nĭ gè mă líng shŭ fān qié nĭ gè xī hóng shì]
In Chinese, '土豆' (potato) and '马铃薯' (also potato), '番茄' (tomato) and '西红柿' (also tomato) are synonyms or regional names. The phrase humorously mocks someone's knowledge, implying redundancy by stating obvious similarities, possibly suggesting a simple or straightforward nature.