切菜刀剃頭 [－－－－头]

Jyutping cit3 coi3 dou1 tai3 tau4
Pinyin qiè cài dāo tì tóu

Definitions (粵典–words.hk)
  1. 語句
    歇後語​，​即​係​牙煙​；​切茶​刀​咁​大​把​，​偏偏​就​攞​嚟​做​剃​頭​呢​啲​咁​精​細​嘅​動​作​，​所以​有​咁​嘅​比喻
    sandwich pun which means dangerous or risky; literally: to shave one's head with a chopper