Add tomatoes, lentils, water or vegetable broth. Start with 2 cups and add more water as needed.
Cook for 40-50 minutes. Taste for more salt and pepper.
This soup can be served with grated Parmesan cheese, or as the Greeks do with a splash of vinegar. You can substitute canned tomatoes with 4 fresh chopped tomatoes with 2 tablespoons of tomato paste or 1/2 can tomato sauce.