Caramelized onion has everything going for it. Through prolonged heat, the onion loses its bite and sweetens. Its aroma with beckon and taunt your neighbors. And it wouldn't dare give you bad breath.
It's also rich enough that you can mix it with non-fat Greek yogurt, and it will still taste indulgent. You could certainly stop there for an unapolegetic crowd-pleaser, but you might want to make it a bit more complex with some competing flavors.
Here, I've used fresh mustard greens that lend bitterness and tickly contrast to the onions' silk. The walnuts add some nubbiness, something to let you know the dip is there as you shovel it down.
RECIPE: Heat 2 tablespoons olive oil in large skillet. Dice 3 large Vidalia onions and place in hot skillet. Cook on medium heat until transparent, then tan, then brown. Stop when the onions look like a chunky marmalade, part goo and part bite, about 45-60 minutes. Cool onions, then add 1 cup non-fat Greek yogurt, and mustard greens and chopped toasted walnuts to taste.