Like last week's character, 心 (xīn/heart), 耳 (ěr/ear) is used on menus both to describe the relevant part of an animal (usually pig/豬/zhū) and in the names of certain vegetables.
This time, though, the vegetables are not leafy greens but rather various edible fungi. I'm not actually sure how many different types of these exist, though the most common Chinese names I see are 木耳 (mù ěr), 銀耳 (yín ěr), 雪耳 (xuě ěr), and 雲耳 (yún ěr). English names include "wood ear", "tree ear", "cloud ear", and "black fungus". There are at least two distinct types of fungi used in Chinese cuisines, one black and one lighter in colour, but I'm still a bit confused about which names go with which fungus. The one I'm most familiar with is the black one, which is sold dried, and corresponds to (at least) 木耳, "wood ear", "tree ear", and "black fungus".
Edit: pulchritude sets me straight in comments: there are two types of black fungus. One is quite large, has a brown back that looks fuzzy when dry, and is usually labelled as 木耳. The other is smaller and softer, and is usually labelled as 雲耳.
I've also seen 耳 used in the name of a Sichuan snack, 葉耳耙 (yè ěr pá). I ate this at Shu Castle on the Old Kent Road in London, where it was translated as "lotus leaf harrow"; I'm not entirely sure of the role 耳 plays in this name, but 葉 is "leaf" and 耙 is "rake" or "harrow".
Here are some dishes with 耳 in the name:
|紅油耳片||hóng yóu ěr piàn||sliced [片] pig's ear [耳] in chilli oil [紅油/"red oil"]|
|紅油耳絲||hóng yóu ěr sī||shredded [絲] pig's ear in chilli oil (this is essentially the same as the above; other names include 紅油豬耳/hóng yóu zhū ěr, which makes the "pig" part explicit)|
|豬耳朵干豆腐絲||zhū ěr duǒ gān dòu fu sī||pig's ear [豬耳朵] with shredded [絲] dry [乾] tofu [豆腐] (朵 means "earlobe")|
|麻辣木耳||má là mù ěr||numbing-spicy wood ear fungus|
|尖椒木耳||jiān jiāo mù ěr||wood ear fungus with chillies|
|木耳肉片||mù ěr ròu piàn||sliced [片] pork [肉] with wood ear fungus|
|耳:||ěr||radical 128 (耳)||Cantodict||MandarinTools||YellowBridge||Zhongwen|