Toss 1 roughly chopped red onion with 2 tablespoons olive oil on a foil-lined baking sheet; season with salt and pepper. Roast at 400˚, stirring occasionally, until golden, 25 to 35 minutes. Set aside to cool. Beat 8 ounces softened cream cheese with a mixer on medium-high speed until creamy, 1 to 2 minutes. Add 1/2 cup sour cream, 1/4 cup grated parmesan, 1 teaspoon Worcestershire sauce, 2 tablespoons each mayonnaise and sliced chives and the roasted onions. Beat until combined. Scrape into a serving bowl.