Bring 4 cups of water to a boil in a pot. Add the tomatoes, onion, potato, carrot, yellow mung dal, ginger, garlic, and
sugar. Boil for 5 to 10 minutes until vegetables are tender.
Strain through a wire mesh, reserving the liquid. Allow the mixture in the strainer to cool, then blend to a smooth purée In a soup pot, combine the blended vegetables with the reserved liquid. Cover and simmer for 15 minutes. Remove from heat, mix in tomato ketchup. Salt to taste.
Serve immediately with freshly ground black pepper. Add 1 teaspoon of half-and-half to each serving and garnish with chopped parsley.