On the Mid-Autumn night, people eat mooncakes, which originated from hundreds of years ago. There are so many kinds of mooncakes, some taste sweet, some are savoury, etc. Most kinds are made with several food ingredients. For example, the most famous kind is "Wu Ren Mooncake," a literally meanings of five kernels: almonds, peach kernels, olive kernels, sesame seeds, melon seeds. Some people don't even like mooncakes very much, but they will eat some on that night, to follow cultural traditions.
In Chinese culture, there are plenty of poetry and stories about the
moon. The most popular one is a fairy tale, about the Goddess Chang's flying to
the moon. Long, long ago, there were 10 suns in the sky, so it was terribly hot on the ground. A man called HouYi was proficient at archery. He shot down 9 of them and left only one. His wife Chang'E was also beautiful and kind. One day HouYi was granted an elixir of life by the Queen Mother of the West and stored it at home. However his brother named PangMeng was bad and coveted ?(desired) immortality. One night, while HouYi was out, PangMeng arrived and forced Chang'E to give him the elixir. Chang'E thought that an immortal bad person would do more bad things and tried to deal with him cleverly.
Finally she had no choice and ate it (and consumed the elixir) herself. Then she floated up
in the air slowly and arrived on the moon at last. And that day was the 8/15 in lunar calendar. On the moon, there was no one else, except
the Moon Rabbit with her. After that, people missed Chang'E and thought that she was lonely there. People blessed Chang'E with her favorite food in the moonlight on that day year by year.
-If it is not sweet, you can just say it is "savoury."
-I'm not sure what you mean by "coveted immortality." My guess is he wanted or desired immortality.