Food & Cooking Recipes Soups, Stews & Stocks Soup Recipes Michael Rulman's Traditional French Onion Soup 3.4 (134) 3 Reviews By Martha Stewart Test Kitchen Martha Stewart Test Kitchen The recipes developed by our test kitchen team have undergone a rigorous process of development and testing, ensuring that every element is optimal, from ingredient amounts to method and cooking time. This process includes triple-testing recipes to ensure they meet our high standards. The many stellar cooks and food editors who have been part of our team include Sarah Carey, Lucinda Scala Quinn, Jennifer Aaronson, Shira Bocar, Anna Kovel, Greg Lofts, Riley Wofford, Lauren Tyrell, and Lindsay Leopold. Editorial Guidelines Updated on March 27, 2020 Print Rate It Share Share Tweet Pin Email Savor the rich flavor of onion in this warm and satisfying recipe from Michael Rulman's "Ruhlman's Twenty." Ingredients 1 tablespoon unsalted butter 7 or 8 pounds Spanish onions (about 10 to 15), thinly sliced Coarse salt Freshly ground black pepper 6 to 12 slices baguette or any other country-style bread, preferably large enough to cover the width of your serving bowls ⅓ cup sherry Red- or white-wine vinegar (optional) Red wine (optional) 1/2 to 3/4 pound Gruyere or Emmenthaler cheese, grated Directions Place a 7 1/2-quart enameled cast-iron pot over medium heat; melt butter. Add onions and sprinkle with 2 teaspoons salt; cover, and cook until onions have heated through and started to steam. Uncover and reduce heat to low; cook, stirring occasionally, until amber and cooked down, about 3 hours. Season with pepper. Meanwhile, preheat oven to 200 degrees. Place bread slices on a baking sheet and transfer to oven. Let dry completely, 20 to 30 minutes. Add 6 cups water to pot with onions; increase heat to high and bring to a simmer. Immediately reduce heat to low. Add sherry; season with salt and pepper. Add a splash of vinegar, if desired, to cut sweetness. For more depth of flavor add a splash of red wine, if desired. Preheat broiler. Divide soup evenly among 4 to 6 ovenproof bowls; top with toasted bread. Divide cheese evenly among bowls. Transfer bowls to broiler; broil until cheese is melted and browned, 3 to 5 minutes. Serve immediately. Rate it Print