I love these curried, sauteed plantains: http://www.seriouslygood.kdweeks.com/2003/10/curried-plantains-2.html

Another option is spiced apples: http://www.seriouslygood.kdweeks.com/2008/11/spiced-apples.html

Here's my favorite side, for this purpose. http://www.food52.com/recipes/3803_pureed_roasted_parsnips_and_butternut_squash_with_creme_fraiche
If you're worried about sweetness, add a tablespoon or two of lime juice at the end, after tasting it. The parsnips add a fun, spicy touch to the squash. It's one of those dishes about which people will ask, "What's in this, anyway? What am I tasting?" Have fun!! ;o)

Pasta salad with a nice vinaigrette travels well, can be eaten at room temp and gets better a day later. Depending on the veggies, cook before hand or raw.

you can roast butternut squash (cubed) with olive oil, kosher salt, 1 tsp of sugar and some thyme or rosemary at 450F for 20 minutes, stir then another 10 minutes. It is my favorite.

This farro salad has a slightly sweet vinaigrette that you may enjoy. And it utilizes whatever seasonal veggies you want to add... http://theheritagecook.com/?p=3583

This sweet potato gratin/galette is fantastic: http://www.food52.com/recipes/1625_sweet_potatoes_anna_with_prunes

What about a not-too-sweet sweet potato casserole, perhaps roasted sweet potatoes and apples, or couscous with butternut squash, apples, and a light maple dressing- Hope this sparks some ideas.