Caramelizing enhances the onion's inherent sweetness. If you can't find sweet onions, substitute two large Spanish onions and add a tablespoon of sugar. This dip is best served warm. If time is tight, you can caramelize the onions (step 2) earlier in the day; combine with the other ingredients and bake just before guests arrive. Serve with a crunchy dipper like Melba toast.
1 tablespoon butter, divided
3 cups diced Rio or other sweet onion (about 2 large onions)
1/4 teaspoon kosher salt, divided
1/2 teaspoon minced garlic
1 cup reduced-fat mayonnaise
1/2 cup light sour cream
1/2 teaspoon garlic powder
1/4 teaspoon freshly ground black pepper
1/4 teaspoon Worcestershire sauce
1/3 cup whole wheat panko (Japanese breadcrumbs)
1 tablespoon chopped fresh parsley
How to Make It
Preheat oven to 350°.
Melt 1 1/2 teaspoons butter in a large skillet over medium-high heat. Add onion and 1/8 teaspoon salt to pan; cook 15 minutes or until tender, stirring occasionally. Add garlic; cook 10 minutes or until onion is golden brown and very tender, stirring occasionally. Remove from heat; cool 5 minutes.
Combine the remaining 1/8 teaspoon salt, mayonnaise, and next 4 ingredients (through Worcestershire sauce) in a medium bowl, stirring until smooth. Stir in onion mixture. Transfer mixture to a 1-quart baking dish coated with cooking spray.
Melt remaining 1 1/2 teaspoons butter. Combine melted butter and panko. Sprinkle panko mixture evenly over onion mixture. Bake at 350° for 15 minutes or until thoroughly heated and bubbly. Sprinkle with parsley. Serve hot.