Dip Ingredients:

2 tablespoons mayonnaise
2 tablespoons sour cream
1 1/2 teaspoons ketchup
1/2 teaspoon Worcestershire sauce
1 tablespoon drained horseradish
1/4 teaspoon paprika
Pinch of cayenne pepper
Kosher salt and freshly ground black pepper

The Onion Ingredients:
1 large sweet onion, such as Vidalia (about 1 pound)
2 1/2 cups all-purpose flour
1 teaspoon cayenne pepper
2 tablespoons paprika
1/2 teaspoon dried thyme
1/2 teaspoon dried oregano
1/2 teaspoon ground cumin
Freshly ground black pepper
2 large eggs
1 cup whole milk
1 gallon soy or corn oil
Kosher salt