In a saucepan over medium heat, add olive oil, onions, carrots and celery. Cook for 5 minutes. Add the turmeric, curry powder, ginger and garlic and cook for another 3 minutes.
Add lentils, vegetarian stock, and tomato paste. Reduce heat to minimum, cover and simmer for 25 minutes.
Finally, add in the cilantro and spinach, and stir until wilted. If the water hasn't absorbed, remove lid and simmer for an additional 5 minutes.