Keep all the ingredients ready for tomato. Peel off the skin of garlic and onion. In a wok/pan, add water, garlic, onion, and tomato.
Let it boil for 4-5 minutes. Switch off the flame. Cool it at the room temperature.
Strain it using the strainer. Do not discard the water. Collect the water in a separate wok. Peel off the skin of a tomato.
Add the boiled tomato, garlic and, onion. Grind it to make a fine puree.
In a wok/pan, add stored water and ground tomato-onion puree. Mix it well.
Add pepper powder and salt, let it boil for 1-2 minutes. Dissolve corn flour in 2 tbsp water, add corn flour in the wok with continuous stirring with a spatula to avoid any lumps in the soup.
Garnish with some chopped coriander leaves, serve hot.