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.
