1Chop the onions, carrots, and celery. Mince the garlic and chop the bacon, if using.
2Heat olive oil in a large pot over medium heat. Add the bacon and cook until lightly crisp.
3Stir in the onions, carrots, celery, and garlic. Add the thyme and red pepper flakes. Cover and cook for 10–15 minutes, stirring occasionally, until softened.
4Stir in the rinsed lentils and pour in the vegetable broth or water. Add the stock cube if desired.
5Bring to a boil, then reduce the heat and simmer for 25–35 minutes, or until the lentils are tender. Add extra broth or water if needed.
6Stir in the cannellini beans and simmer for another 5–10 minutes.
7Taste and add salt and black pepper as needed.
8Ladle into bowls, sprinkle with fresh parsley, and finish with a drizzle of extra virgin olive oil.