Bring a pot of water to a boil.
Wash and rinse tomatoes. Place tomatoes in boiling water for 2 minutes so they blanch and skin can be easily peeled off.
Drain tomatoes and let them cool.
Peel tomatoes once cooled and set aside.
Place peeled tomatoes, 1/2 tsp cumin seeds, peppercorns, coriander powder, grated ginger, salt, and sugar in a blender and blend until fully combined.
Pour into a pot on the stove on low-medium heat so that it warms up again.
Add in coconut milk to the pot for creaminess. Stir well. Keep soup on low heat so it continues heating. Note: Adding coconut milk is completely optional, but I prefer the creamy texture of the soup when coconut milk is added.
Meanwhile, in a separate small pan, heat 1 tbsp ghee or coconut oil. Once hot, add mustard seeds and let them temper (they will pop).
Once the popping slows down, add 1/2 tsp cumin seeds and curry leaves and fry in oil for 1 more minute. Pour this on top of the soup. Give it a good stir.
Once the soup is fully heated, taste and adjust spices/seasonings to your liking (especially salt).
Ladle into bowls or mugs. Garnish with lots of freshly chopped cilantro. Serve hot!