3 sliced medium onions (about 4 1/2 cups), divided
1 teaspoon sugar
1/4 teaspoon kosher salt
1/4 teaspoon freshly ground black pepper
1/2 cup plain reduced-fat (2%) Greek yogurt
1/8 teaspoon ground nutmeg
1/2 teaspoon sherry or red-wine vinegar
1/2 teaspoon Worcestershire sauce
How to Make It
In a large nonstick skillet, heat oil over medium. Add onions, sugar, salt, and pepper. Cook, partially covered and stirring occasionally until deep golden and tender (about 25 minutes). Reserve 1 tablespoon onions; set aside. Allow caramelized onions to cool; coarsely chop.
In a medium bowl, combine chopped onions with yogurt, nutmeg, vinegar, and Worcestershire. Top with reserved onions.