Rinse the Lentils: Wash the lentils thoroughly to remove any debris. If you're using dried lentils, they typically don’t need soaking, but a quick 30-minute soak can speed up cooking. If using canned lentils, drain and rinse them.

Prep the Vegetables: Dice the onion, carrot, and celery into small pieces. Mince the garlic and chili (if using).

Sauté the Base: Heat olive oil in a large pot over medium heat. Add garlic and chili (or onion, carrot, and celery for a soffritto), and sauté until fragrant and soft (about 3-5 minutes).

Add Potatoes (Optional): If using potatoes, add the cubed potatoes to the pot and cover them with cold water to prevent discoloration. Let them sit for a moment before adding them to the pot with lentils.

Simmer: Add the lentils and potatoes (if using) to the pot along with the broth or water. Bring to a gentle simmer, and cook for 30-40 minutes or until the lentils are tender. Stir occasionally and add more liquid if necessary to maintain your desired thickness.

Add the Spinach: Stir in the spinach (fresh or frozen) for the last 2-3 minutes of cooking, allowing it to wilt and brighten.

Season: Taste the soup for seasoning. Add salt and freshly cracked black pepper to taste.

Finish: For a rich, glossy finish, drizzle with extra-virgin olive oil. Optionally, top with crumbled feta or primo sale cheese for extra flavor.

Serve: Ladle into bowls, drizzle with more olive oil, and enjoy with a side of toasted bread or crostini.