Heat four tablespoons of oil in a large stock pot over medium-high heat. Cook the onion and garlic for 3 minutes until fragrant and golden.
Turn the heat up to high, add the chopped sausage and cook until fragrant and brown. Next, add the spices and herbs and cook them for two minutes.
Add carrot, and celery, and keep cooking for a couple of more minutes.
Add in the water, stock, tomato, and lentils. Stir and bring the soup to a simmer, place the lid on and reduce heat to medium-low. Simmer for 30 minutes.
Add the zucchini & green beans. Simmer 30 minutes longer or until the lentils are fully cooked but still hold well their shape.
Adjust sea salt to taste. Dice 4oz of parmesan. Serve soup in bowls with a tablespoon of diced parmesan stirred in the soup and shavings on top.