If you don't have a particular ingredient for a recipe, chances are you have something on hand that could act as a substitute, and there is a whole chart of interchangeable mix - and - match ingredients in the book to help you work through that. (golubkakitchen.com)
We have a whole chart / article about this if you're interested. (thelittlepine.com)
Dr. G and team: if you make a version of this vid for kids in schools, you could make the phytonutrient point visible by shrinking the whole chart (down to a thin line, if you have to) to show the hundreds more green squares. (nutritionfacts.org)