Final answer:
The flashback in chapter 7 of 'Holes' is Stanley's grandfather falling in love with Myra Menke, which adds depth to the family curse theme.
Step-by-step explanation:
The event from chapter 7 of Holes that is related as a flashback is Stanley's grandfather falling in love with Myra Menke. This particular piece of the story takes the reader back in time to reveal a part of Stanley Yelnats' family history, distinguishing it from the present moments of Stanley digging holes at Camp Green Lake. Flashbacks serve as a literary device to provide backstory and add depth to the character's current situation. In this case, it helps to build the multi-generational curse that is a central theme in the novel Holes.