This is my favorite Onion Soup Recipe. Made by slowly caramelizing six different types of onions, it’s comforting, fragrant, flavorful, and especially delicious when topped with baked Parmesan crisps or gooey melted cheese.
Six Onion Soup
French Onion Soup has always been one of my favorite soups. When I was younger I would always request that the toasted bread be served on the side of the soup and extra cheese on top. After all, soupy caramelized onions covered with cheese is the very best food combination ever.
This delicious onion soup, while not exactly like French onion soup, is very similar. So if you love the French version then I’m confident that you’ll love this one, too.
And the flavor!? Deep, complex, and exactly what one should expect when slowly cooking six different types of onions until jammy and caramelized.
What types of onions are in this onion soup?
- Green onions
- Red onions
- White onions
- Yellow onions
How to Make Onion Soup
1. Caramelize the onions:
Start with 2 tablespoons of olive oil and 2 tablespoons of butter in a large heavy-bottomed Dutch Oven or stockpot set over medium-high heat. Add the leeks, first, cooking for about 5 minutes before adding the sliced shallots. Throughout this entire process, remember to stir frequently to prevent burning. Cook for an additional 5 minutes or so. Next, add the green onions, white onions, red onions, yellow onions, salt, and black pepper. If all of the onions don’t fit into the pot all at the same time, that’s ok. Add as many onions as you can, allow them to cook down, and then add the rest. Add the remaining 2 tablespoons of olive oil and 2 tablespoons of butter. Mix well and stir frequently.
Allow the onions to cook until softened, golden-brown, fragrant, and jammy. This will take at least 60-90 minutes. Learn more about how to caramelize onions here.
In the final 15 minutes, stir in the garlic, fresh parsley, rosemary, and fresh thyme. Continue to stir often.
2. Add the broth:
Once the onions are deeply golden-brown and caramelized, increase the temperature to high heat. Add the dry sherry (or cognac) and scrape up any brown bits stuck to the bottom of the pot. Allow the alcohol to cook and reduce for 1-2 minutes before adding the beef broth.
Cover your pot and bring to a boil, then reduce heat to a simmer and cook for 20-30 minutes. Season with additional salt and pepper, to taste.
- Increasing the heat will not caramelize your onions any faster. The process of caramelizing onions is a slow process, but well worth it!
- Swap the dry sherry for additional stock or broth to make this soup alcohol-free.
- To make this soup vegan, trade the butter for additional cooking oil and use vegetable broth instead of beef broth.
- Keep leftovers stored in the refrigerator for up to 4-5 days.
How to Serve
Serve this delicious onion soup with baked parmesan crisps (recipe in the recipe card below), fresh bread, homemade croutons, or grilled cheese. I also highly recommend a little cheese sprinkled over the top – parmesan cheese, asiago, and gruyere are all highly recommended. Finally, I like to round things out with a small side salad like this arugula salad or tomato salad.
Have you tried making this Easy Onion Soup Recipe?
Tell me about it in the comments below! I always love to hear your thoughts. And tag me #theforkedspoon on Instagram if you’ve made any of my recipes, I always love to see what you’re cooking in the kitchen.
Onion Soup Recipe
- 4 tablespoon olive oil - divided
- 4 tablespoon butter - divided
- 6 cups leeks - white and light green parts only, halved and thinly sliced
- 8 large shallots - thinly sliced
- 2 cups green onions - thinly sliced
- 6 sweet white onions - halved and thinly sliced
- 4 red onions - halved and thinly sliced
- 3 yellow onions - halved and thinly sliced
- 2 teaspoon salt
- 1 teaspoon fresh ground black pepper
- 10 cloves garlic - minced
- 1 cup fresh parsley - finely chopped
- 2 tablespoon fresh rosemary - finely chopped
- 2 tablespoon fresh thyme - finely chopped
- ⅔ cup dry sherry - (may substitute with cognac or additional beef broth)
- 8-12 cups beef broth
- Fresh chopped parsley - to garnish
For the Baked Parmesan Crisps
- 1 French or Sourdough baguette - sliced into 1/2-inch thick pieces
- 3 tablespoon olive oil
- 1 cup Parmesan cheese - shredded
For the Soup
- Place 2 tablespoons of olive oil and 2 tablespoons of butter in a large heavy-bottomed Dutch Oven or stockpot set over medium-high heat. Add the leeks and cook, stirring often, until starting to soften (approximately 5-6 minutes). Add the sliced shallots to the leeks and mix well to combine. Continue to cook, stirring frequently, for 3-4 minutes. Add the sliced green onions, white onions, red onions, yellow onions, salt, and black pepper.
- If you find that all the onions refuse to fit into the pot, that's ok! You may need to add part of the onions, allow them to cook down, add some more onions, allow those to cook down, and then add the rest.
- Drizzle the remaining olive oil over the onions and add the remaining 2 tablespoons of butter to the pot. Cook the onions, stirring frequently until softened, deeply golden-brown, and jammy (about 60-90 minutes). In the last 15 minutes, stir in the garlic, fresh parsley, rosemary, and thyme. Mix well.
- With the onions deeply browned and caramelized, increase the temperature to high and add the dry sherry (or cognac) and scrape any burnt pieces stuck to the bottom of the pot. Allow the alcohol to cook for approximately 1-2 minutes before adding the beef broth to the pot. Cover and bring to a boil, then reduce the heat to low. Simmer for an additional 20-30 minutes and season with additional salt and pepper, as needed.
- Serve each bowl topped with homemade baked Parmesan crisps (see below), fresh chopped parsley and additional shredded cheese, if desired.
For the Baked Parmesan Crisps
- Prepare the Parmesan crisps approximately 15 minutes before the soup is ready to be served. Position the baking rack in the upper third of the oven and preheat the broiler to low.
- Slice the baguette into thin 1/2-inch slices and transfer to a baking sheet in a single layer. Brush the top side of each slice with oil. Transfer baking sheet to the oven and broil until golden brown, approximately 4 minutes.
- Remove the baking sheet from the oven and immediately flip over each slice and top with approximately 1 tablespoon of shredded Parmesan cheese. Return the baking sheet to the oven and broil an additional 3-4 minutes or until the cheese has melted. Serve.
(Nutrition information provided is an estimate and will vary based on cooking methods and specific brands of ingredients used.)