I need a vegetable dish that will go with Pork Tender

I just recently made a cauliflower-rutabaga puree as a side for pork which worked wonderfully. I braised a head of cauliflower (cut into florets) in butter until tender, and simmered 3 small quartered rutabagas in water until tender, and then puréed the two together with a little more butter and a little warm half-and-half (and S&P of course). It's pretty rich though, so an additional side of something green and acidic would work well (I made a green salad but I also think brussel sprouts in an acidic vinaigrette or balsamic glaze would pair well).

I like Ms. James suggestion. Also, sweet potatoes in any form will also pair well.

Green beans + new potatoes in a sharp, mustardy vinaigrette with some parsley and finely chopped fennel and celery - sort of like a warm German potato salad but more interesting and minus the bacon -- would be a nice side with pork tenderloin, and not at all too bland. ;o)

Two of my favorites on this site: One Pot Kale and Quinoa Pilaf and Kale Gratin.

How about Merrill's shaved Brussels sprout salad
https://food52.com/recipes/7650-shaved-brussels-sprout-salad-with-red-onion-lemon-and-pecorino

If you're interested in sauteed apples and onions, or sauteed red cabbage, let me know and I can post some recipes for you