Add chopped amla, turmeric powder, green chilies, and thippili to a pot with 2 cups of water and boil until the amla softens.
Lightly mash the softened amla or blend to a smooth consistency if preferred.
Mix in black pepper, coarsely ground cumin seeds, and rasam powder.
Add cooked and mashed toor dal, adjusting the consistency with water if required.
Add salt and bring the rasam to a gentle boil, simmering for 5 minutes.
Heat ghee in a small pan, add mustard seeds, and let them splutter. Add cumin seeds and curry leaves, sautéing for a few seconds.
Pour the prepared tempering over the rasam and mix well.
Garnish with chopped coriander leaves and serve hot as a soup or with steamed rice.