Random Cantonese Phrase -of-the-Day:
生骨大頭菜 [🥮 saang¹ gwat¹ daai⁶ tau⁴ coi³]
Meaning: Spoiled brat (slang)
Literal meaning: Big head vegetable that produces bones.
Story behind the saying: 大頭菜 (literally means "big head vegetable”) is an umbrella term for root vegetables from the mustard greens family; it is commonly mistaken for the turnip (from the Wiki entry on 大頭菜：「大頭菜常誤稱蕪菁」) and when people (at least from Hong Kong and Guangdong areas, I think?) say 「大頭菜」, they usually have the turnip in mind.
Anyway, I'm not a horticulturist and am not qualified nor am I going to go into the scientific classifications of the myriad of veg. cultivars out there; the main takeaway is just to know that 大頭菜 refers to some kind of turnip-like root vegetable.
And when the 大頭菜 crop is not so good, the vegetable fibres will be coarse and rough, leaving a fibrous residue in the mouth making the vegetable difficult to swallow; likened to trying to swallow bones. When Cantonese-speaking farmers have a bad crop of 大頭菜, they will say they have 「種壞」 — “grown badly”, which is a homophone for 「緃壞」 (🥮 zung³ waai⁶) — “to pamper/spoil (a child/someone) rotten.
Hence, 「生骨大頭菜」 is a 歇後語 (anapodoton) to mean/refer to someone as a "spoilt brat”.