"Oh-wow" main dishes and photogenic desserts are often the stars at the potluck. The side dish is an afterthought. Just bring green beans, they say. A casserole, perhaps. But the side dish is far more than just the sidekick that is only useful for palate-cleansing or nutritional heft. The side dish can be beautiful; it can tantalize the taste buds. A good side dish can be a scene-stealing, freewheeling powerhouse at any potluck.