Heat the olive oil in a large soup pot over medium heat. Add the onion, carrots and celery. Saute for 5-7 minutes until softened.
Add garlic and sundried tomatoes, cooking for 1-2 minutes, until fragrant.
Stir in the tomato paste, Italian seasoning and sea salt.
Add the lentils, diced tomatoes, water, bay leaf. Bring to a boil, then reduce the heat to low. Cover and simmer for 25-30 minutes (until the lentils are tender).
Stir in the coconut milk and the spinach. Let spinach wilt for 2-3 minutes.
Remove the bay leaf. Add salt and pepper to taste.