Lively Up Yourself Lentil Soup

Modified from 101 Cookbooks.
Ingredients:
2 cups black beluga lentils (or green French lentils), picked over and rinsed
1 tablespoon extra virgin olive oil
1 large onion, chopped
1 teaspoon fine-grain sea salt
1 28-ounce can crushed tomatoes
2 cups water
3 cups of a big leafy green (chard, kale, etc), rinsed well, deveined, finely chopped
light sour cream

Bring 6 cups of water to a boil in a large saucepan, add the lentils, and cook for about 20 minutes, or until tender. Drain and set aside.
Meanwhile, heat the oil in a heavy soup pot over medium heat, then add the onion and salt and saute until tender, a couple minutes. Stir in the tomatoes, lentils, and water and continue cooking for a few more minutes, letting the soup come back up to a simmer. Stir in the chopped greens, and wait another minute. Taste and adjust the seasoning if need be. Ladle into bowls, and serve with a dollop of light sour cream.