Simple French Onion Lentil Soup
This French Onion Lentil Soup is a cozy twist on classic French onion soup. It combines deeply caramelized onions, hearty green lentils, savory broth, and Italian seasoning, then finishes with crusty sourdough or baguette topped with melted Gruyère cheese.
It’s simple, comforting, and makes a hearty meal on a chilly day. I love that this adds a hearty twist to French onion soup. It heats up well for leftovers and is a simple soup to put together. I hope you enjoy it as much as I do!
Ingredients
Method
- Melt butter and avocado oil in a large pot over medium heat. Once the butter begins to sizzle, add the sliced or diced onions. Cook for 30–40 minutes, stirring occasionally, until the onions are soft and caramelized.4 large onions, 2 tablespoons butter, 2 tablespoons avocado oil
- Add the sea salt, flour, and minced garlic. Stir and cook for 2 minutes.1 teaspoon sea salt, 2 tablespoons all-purpose flour, 2 cloves garlic
- Pour in the chicken stock or vegetable broth, red wine vinegar, Italian seasoning, and dry green lentils. Increase the heat and bring to a boil.6 cups chicken stock or vegetable broth, 1/2 cup red wine vinegar, 1 –2 tablespoons Italian seasoning, 1 cup dry green lentils
- Cover the pot, reduce the heat to low, and simmer for 25–30 minutes, or until the lentils are tender.
- While the soup simmers, slice the sourdough bread or baguette and place the slices on a cookie sheet. Top with shredded Gruyère cheese and broil for 2–4 minutes, until the bread is toasted and the cheese is melted and bubbly. Watch closely to prevent burning.1 cup shredded Gruyère cheese, Sourdough bread or a baguette
- Ladle the soup into bowls and top with the cheesy bread. Serve warm.
Ingredients
- 4 large onions, thinly sliced or diced
- 2 tablespoons butter
- 2 tablespoons avocado oil
- 1 teaspoon sea salt
- 2 tablespoons all-purpose flour
- 2 cloves garlic, minced
- 6 cups chicken stock or vegetable broth
- 1/2 cup red wine vinegar
- 1–2 tablespoons Italian seasoning
- 1 cup dry green lentils
- 1 cup shredded Gruyère cheese
- Sourdough bread or a baguette, sliced
Instructions
1. Caramelize the onions
In a large pot, melt the butter over medium heat and add the avocado oil.
Once the butter begins to sizzle, add the sliced or diced onions. Cook for 30–40 minutes, stirring occasionally, until the onions are soft, golden, and caramelized.
2. Add the garlic and flour
Add the sea salt, flour, and minced garlic to the onions. Stir well and continue cooking for about 2 minutes.
3. Add the broth and lentils
Pour in the chicken stock or vegetable broth, red wine vinegar, and Italian seasoning. Stir in the dry green lentils.
Increase the heat and bring the soup to a boil.
Once it reaches a boil, cover the pot and reduce the heat to low, keeping the soup at a gentle simmer.
Cook for 25–30 minutes, or until the lentils are tender.
4. Make the cheesy bread
While the soup is simmering, slice your baguette or sourdough bread and arrange the slices on a cookie sheet.
Top each slice with shredded Gruyère cheese.
Place the bread under the broiler for 2–4 minutes, watching it closely, until the bread is toasted and the cheese is melted and gooey.
For more browned, bubbly cheese, leave it closer to 4 minutes.
5. Serve
Ladle the hot French Onion Lentil Soup into bowls and top each bowl with a piece of the cheesy bread.
Serve warm and enjoy!
Notes
- Save yourself some prep time: I sometimes buy onions that are already chopped and ready to use.
- Choose your bread: Sourdough gives this soup a delicious rustic flavor, but a crusty baguette works beautifully, too.
- Make it your own: Use chicken stock for a richer flavor or vegetable broth for a vegetarian option.
- Watch the broiler: The cheese can go from perfectly golden to burnt quickly, so keep a close eye on it.
