I discovered just recently while on a trip to Nagano prefecture that in Japan they grow some sticky millet. It looks very much like millet but once cooked it is much stickier.
I found this consistency perfect for vegan croquettes. So I mixed some boiled sticky millet with some vegetables sautéed I had in the fridge: a leek, half new onion, 2 small carrots gratted, one egg and a few linen seeds, and made croquettes that I cooked in olive oil in a frypan.
I also made a version with cheese but taste-wise without was really delicious and if the cheese makes the croquettes creamy and more golden, I don't think it is a must.