a difficult problem to me

Since we don't eat Chinese breakfasts, that's difficult to say. A western breakfast can be large or small. A small breakfast would be a pastry--such as a croissant or a danish--and tea or coffee, and maybe also some fruit juice. A large breakfast might include fried meat of some kind--usually pork, in the form of sausage or bacon--and fried eggs, fried potatoes and some form of bread, as well as coffee and/or juice. For some people, breakfast is a hot or cold cereal, which is made from grain such as wheat or oats, and, as always, tea or coffee, and perhaps juice.

There are many, many different things which people eat for breakfast in western nations, and they change from nation to nation. Bacon means something different in the United States, Canada and England--so there's a lot of variety.