Slice 3 large yellow onions into ¼-inch thick strips. Heat 2 tablespoon butter or olive oil in a large skillet over medium-low heat until melted and shimmering, about 1 minute.
3 large yellow onions, 2 tbsp butter or olive oil
Add sliced onions to the skillet and sprinkle with ½ teaspoon salt. Stir to coat onions in fat. Cook over medium-low heat for 40-45 minutes, stirring every 5 minutes to prevent sticking and burning. If onions stick, deglaze skillet with 1-2 tablespoon water. Onions should become deep golden brown and tender without black edges.
3 large yellow onions, 0.5 tsp salt
Transfer caramelized onions to a plate and allow to cool for 10 minutes until soft and jammy. Discard any burnt pieces.
3 large yellow onions
In a mixing bowl, combine 1 cup sour cream, ½ cup mayonnaise, 1 clove minced garlic, ¼ teaspoon black pepper, 1 teaspoon lemon juice, and 1 teaspoon Worcestershire sauce if using. Stir until smooth.
1 cup sour cream, 0.5 cup mayonnaise, 1 tsp lemon juice, 1 clove garlic, 0.25 tsp black pepper, 1 tsp Worcestershire sauce
Chop cooled caramelized onions into smaller pieces if needed and fold them into the dip base until evenly distributed. Cover and refrigerate for at least 2 hours to chill and develop flavor. Garnish with 2 tablespoon chopped fresh chives or parsley before serving.
3 large yellow onions, 2 tbsp fresh chives or parsley
