Prep: 30 m
Cook: 4 h 35 m
Ready:5 h 5 m
6 tablespoons butter
4 large yellow onions, sliced and separated into rings
1 tablespoon white sugar
2 cloves garlic, minced
1/2 cup cooking sherry
7 cups reduced-sodium beef broth
1 teaspoon sea salt, or to taste
1/4 teaspoon dried thyme
1 bay leaf
8 slices of French bread (optional)
1/2 cup shredded Gruyere cheese (optional)
1/3 cup shredded Emmental cheese (optional)
1/4 cup freshly shredded Parmesan cheese (optional)
2 tablespoons shredded mozzarella cheese (optional)
Note: I always removed bread whenever I do this. So it’s all entirely up to you.
1. Heat butter in a large, heavy pot over medium-high heat; cook and stir onions until they become translucent, about 10 minutes. Sprinkle onions with sugar; reduce heat to medium. Cook, stirring constantly, until onions are soft and browned, at least 30 minutes. Stir in garlic and cook until fragrant, about 1 minute.
2. Stir sherry into onion mixture and scrape bottom of pot to dissolve small bits of browned food from the pot. Transfer onions into a slow cooker and pour in beef broth. Season to taste with sea salt; stir in thyme and bay leaf. Cover cooker, set on High, and cook 4 to 6 hours. If desired, set on Low and cook 8 to 10 hours.
3. About 10 minutes before serving, set oven rack about 8 inches from the heat source and preheat the oven’s broiler. Arrange bread slices on a baking sheet.
4. Broil bread slices until toasted, 1 to 2 minutes per side.
5. Combine Gruyere, Emmental, Parmesan, and mozzarella cheeses in a bowl, tossing lightly. Fill oven-safe soup crocks 3/4 full of onion soup and float a bread slice in each bowl. Top with about 2 tablespoons of cheese mixture per serving.
6. Place filled bowls onto a baking sheet and broil until cheese topping is lightly browned and bubbling, about 2 minutes.
Note: You do not HAVE to caramelize the onions, you CAN simply melt the butter in your crock, add the onions to coat them and then add all the ingredients and cook. HOWEVER, caramelizing the onions makes for a much much better soup!!!! 🙂 If you like, simply put all the options out on the table and let people make their own! This seems to be the popular method when I have a craft night. People can make their own decisions about what they want in or on their soup!