Heat a large pot with the oil. Add the onion and cook about 4 min, stirring occasionally. Add the salt and garlic and cook about 30 s.
Add the tomatoes. Reduce the heat to low and simmer about 10 min. or until puree.
Pour the water, broth, lentils, potatoes. Cover the pot and bring to the boil. Reduce the heat to low and simmer the soup about 10 min. or until the veggies and lentils are fork-tender.
Add the red wine vinegar, sugar, salt, oregano, basil. Turn off the heat.
Transfer 1/2 of the soup to a big bowl. Blend until puree. Pour back into the pot.
Let the soup sit for about 10 min.