Why Do the Lions Eat Lettuce?
Lettuce is the staple food of lions in Southern Chinese Lion Dancing. The reason for this, as is common with symbolic foods in Chinese culture, the phonetic associations of the word "lettuce" in Chinese. "Sang Coi" (cantonese) is an adjective-noun construction which literally means "raw vegetables". However, the character which means "raw" can also mean "to produce" or "to create". By changing the tone of the second character, we can get the meaning "wealth"; and so we now have a verb-object construction meaning "to get rich". Thus the Chinese word for "lettuce" sounds almost identical to the construction "to get rich", with the exception of a tone change on one of the characters.
A different way to address lettuce in Chinese is "Ceng", here as a noun meaning "greens". This character also sounds just like "Qing" of the Qing Dynasty. As many people at the time were opposed to the Manchurians being in power, spitting out greens took on a new meaning, "Faan Ceng Fuk Ming" or "resist the Qing Dynasty and revive the Ming Dynasty."
Another favorite food of the Chinese lion is the Onion, "Cung", which is a homophone of another character meaning "wisdom".
Therefore, because the lion has the potential to bring wealth and wisdom to anyone who invites it to do so, the Chinese regard the lion as an omen of good luck.