Cooks Illustrated Onion Soup Recipes

Steps:

• Melt butter in a heavy Dutch oven over medium heat. Add onions and 1/2 teaspoon salt, stir and cover, letting onions soften for 5 minutes. Remove lid and let onions caramelize until golden brown over medium heat, stirring occasionally. Adjust heat if onions are browning too quickly. The caramelization process may take 45 to 60 minutes.
• Meanwhile, warm broth in a saucepan over low heat.
• Once onions are caramelized, add wine and sherry to the pot and allow mixture to come to boil. Stir in flour and let thicken for a minute or two.
• Slowly add warm broth, 1/4 teaspoon salt and the pepper to the onion mixture and boil uncovered for 10 minutes. Add more salt and pepper to taste.
• Heat the broiler, and arrange individual ovenproof casseroles on a baking sheet. Ladle soup into casseroles, and cover top with bread slices. Sprinkle each casserole generously with Gruyère. Broil for a minute or two, watching carefully, until cheese melts and browns. Serve immediately.

Steps:

• In a large Dutch oven or other large pot, melt 3 tablespoons butter over medium heat. Add the oil and onions; cook onions are until softened, stirring occasionally, about 15 minutes. Add the salt, pepper, and sugar; continue to cook, stirring occasionally, until onions are deep golden brown and caramelized, reducing heat slightly if onions seem to be browning too quickly, 35 to 45 minutes more.
• Add wine and raise heat to high. Cook until almost all liquid has evaporated, 8 to 10 minutes.
• Tie thyme and bay leaves into a bundle with twine. Add broth and herb bundle to pot with onions. Bring to a boil, reduce to a simmer, and cook, uncovered, until broth is thickened and flavorful, 20 to 30 minutes. Remove from heat and whisk in remaining 2 tablespoons butter. Taste and adjust seasoning.
• Heat the broiler. Cut two 1/2-inch baguette slices for every serving of soup. Place baguette slices on a rimmed baking sheet and toast in oven until crisp and dry but not browned, about 1 minute per side. Rub one side of each toast with the garlic clove and set aside.
• Place ramekins or ovensafe bowls on a rimmed baking sheet, add 1/2 teaspoon of sherry to the bottom of each, and ladle soup on top. Top each serving of soup with two garlic-rubbed toasts. Divide cheese among the servings, covering the bread and some of the soup. Carefully transfer baking sheet to oven and broil until cheese is melted and bubbling, 4 to 8 minutes. (Alternatively, if using regular soup bowls: Top each garlic-rubbed toast with some cheese and return to broiler to melt, about 2 minutes more. Divide sherry and soup among bowls, sprinkle with remaining cheese, and top each serving with two cheese toasts.)

Steps:

• Place sliced onions and butter into slow cooker, and mix until onions are thoroughly coated. Stir in bread and chicken broth.
• Cover, and cook on LOW for 10 to 18 hours or on HIGH 4 to 5 hours, stirring occasionally. Stir well during last hour.