Nothing Fancy: Diana Kennedy (2019) was written and directed by Elizabeth Carroll. This film is a creative mixture of interview, contemporary footage, and historic footage.
Diaba Kennedy--still alive and well at age 97--is a world-renowned expert on Mexican cooking. She has written nine cookbooks, each one about the cuisines of Mexico. She has traveled extensively throughout Mexico, and has gathered recipes wherever she goes.
This movie has an anemic IMDb rating of 6.6. I think that's because Kennedy isn't a sociable or even very likable person. Basically, there are only two ways of doing Mexican cooking--her way or the wrong way. Someone that opinionated and self-assured doesn't make for a happy movie.
My thought is that Kennedy is Kennedy, and the movie showed her as she is. You can form your own opinion about whether you'd like to invite Kennedy over for dinner. I rated the movie based on how well I thought it reflected Kennedy's work and personality, and rated it 9.