Painting with vegetables is another project I believe I tried while teaching during my public school days and only recently attempted at homeschool.
The idea sparked in my mind after reading Apple Fractions by Jerry Palotta. This is a book which leads kids (and fun seeking adults) to naturally want to cut up apples to extend mathematical learning. And once the apples are cut up, they look surprisingly like penguin parts! So we grabbed the paint and set about making penguin pictures in conjunction with our penguin week learning. (We added some halved potato parts for the penguin bodies.)
The penguins are pictured here at the top of our craft display wall (the kitchen door!!).