CatI had a shepherds' pie with a mash made of canelinni beans, chick peas, black peas and green lentils. With cavolo nero.
It was an experiment...
It was good. The ratio of top to bottom was off though and the mash was a bit claggy and gritty so I need to take out some of the ingredients.
Here's a few different twists on the classic Shepherds pie, you may or may not want to try.
18 Creative and Comforting Twists on Classic Shepherd's Pie