I said I was going to try it and I did! I added 4 small red beets, peeled and diced, to my pressure cooker full of apples, and instead of using water, I used juice and a little cinnamon. I love to roast baby beets with orange and cinnamon, so I thought it could work in this case. I would've used orange juice, but we only had TJ's Orange Mango. (You know what's in it? The first ingredient in TJ's Orange Mango is apple juice!)
I loved the result. Bright red and a little chunky, very sweet and nutritious in a different kind of way. Probably lower in calories too, since beets have fewer calories than apples.
Red Beet Applesauce
3-4 lbs of fuji, gala, or another sweet variety of apple, quartered
If using the pressure cooker cut the apples in big chunks because they will cook faster than the beets which need to be in a very small dice (1/4 in.) or shredded, no need to peel the apples as everything will go through the food mill. Add juice and cinnamon if using, bring pressure to high, cook 10 min, let pressure release naturally. When cool enough to handle run through the food mill.