As the onions cook, stir together ¾ cup sour cream, ¾ cup yogurt, 3 to 4 teaspoons onion powder, ½ teaspoon salt and ½ teaspoon dried sage. Add the onion powder to taste. I pretty much used the full 4 teaspoons because the onion powder is what gives this that sweet French flavor. Add a bit at a time until it tastes the way you want it. Set aside until the caramelized onions and garlic have cooled to room temperature. Stir in the onions, adding 1 teaspoon lemon juice at this time, to taste, as well. Add fresh chopped chives, reserving 1 tablespoon to garnish on top, if desired.