And another idea .... roasted beets!
I do a mixture of veggies (whatever I have at the time ... potatoes, onions, carrots, celery, sweet potatoes, parsnips, and/or beets) with seasonings. Roast in a flat pan in the oven. I keep the beets in a corner by themselves to minimize the staining, but at serving time, then toss them all together .
The little bit of staining at that point is good ... puts a rosey glow on the whole mixture. And oh so delicious!