Hmmm, I was thinking something really basic like green beans, spinach, or broccoli - no real recipe involved since it already sounds like you've got two "recipe" dishes going.
Here's my favorite way to cook green beans, a la Julia Child:
Trim your green beans. Blanch them for about a minute in a pot of boiling water. Shock them in a bowl of ice water to stop the cooking and set the color. Dry them off, then saute them over medium-high heat in some butter until they start developing a few dark patches (but don't overcook them to dull green; they should still be pretty bright green and tender-crisp). Squeeze half a lemon over and add some lemon zest in the last minute of cooking.
Or how about this recipe for sweet potatoes cooked with apples? Healthy, but should appeal to sweet-toothed kids, and seasonal:
http://www.vegkitchen.com/sweetpotatoes.html#bak
This cranberry slaw sounds yummy too if you do coleslaw
http://www.vegkitchen.com/simple.html#cra
HTH!