Caramelized Onion Mashed Potato Soup!

Name: Caramelized Onion Mashed Potato Soup!
Ingredients: 3 large onions, peeled, halved and sliced in the food processor; 2 tablespoons butter; 2 tablespoons olive oil; 6 garlic cloves, sliced; 1 teaspoon pepper; 1 pinch chili pepper flakes; bay leaf; 1⁄2 teaspoon thyme; 1 teaspoon sugar; 1⁄3 cup sherry wine; 4 cups low sodium nonfat beef broth; 1 tablespoon Worcestershire sauce; 1 teaspoon dried parsley; 2 cups leftover mashed potatoes; Optional; 4 -6 slices toasted bread (I used croissant halves); 1 -1 1⁄2 cup of grated swiss gruyere; scallion, thinly sliced, for garnish