Company's Coming, which also appears to have been rereleased in 2018. Company's Coming had a huge impact on my life, as I explained in a 2015 OC post. Basically, what happened was:
"The day after I read it to my sons, it inspired my short story, How Mom Saved the Planet, which was later published in Cricket Magazine. And another version of How Mom Saved the Planet became the first chapter of my first book, My Life Among the Aliens. I may not have had a writing career, if not for Company's Coming."
Company's Going picks up with the same characters from Company's Coming, except now Moe and Shirley's alien guests are so taken with Shirley's cooking that they invite her to cater a wedding back on their home world. It's just as terrific as the first book.
Interesting point: My Life Among the Aliens also had a sequel, Club Earth. Both books were a series of stories about Will and Rob, whose mom's over-the-top healthy cooking attracts aliens. In their case, though, the aliens came to them.
Another interesting point: Both the Company books are examples of picture books with no human characters and no animals characters filling in for humans. I don't see that a lot.
Both of what I call the Will and Rob books have human characters. And aliens, of course.