https://www.life.com/history/up-close-and-personal-with-apollo-11-a-life-photographers-story/ (about two thirds of the way down the page)

The magazine whose photographer took this describes it as "Home from work after his family had already eaten, Neil Armstrong ate his customary late dinner while reviewing the Wall Street Journal stock market numbers, March 1969."

Supposedly his actual breakfast on the day of the mission was steak, eggs, and toast, but I can't find a source for that which isn't the Mirror, so I'll take that with a pinch of salt