Heat the oil in a saucepan over medium heat. Lightly brown the ginger. Add carrots and celery. Stir fry two minutes.
Add the tomatoes, salt, sugar, and pepper. Cook until tomatoes are mushy.
Let the tomatoes cool, then puree in blender.
Heat the oil in a saucepan. Add the cumin seed and asafetida. As the cumin seeds crack, add cilantro and stir for a minute.
Add the tomato pure and approx. 1¼ cup of water (adjust the water to your taste).
When the soup boils, turn the heat to low and let it simmer three to four minutes.
Serve hot, I like to serve with few pieces of crouton.