• Rinse and pressure cook toor dal until mushy. Drain the cooked dal and retain the dal cooked water. Mash the dal well.
• Take dal cooked water in a pot and add about 1.5 cups of water to it. We need around 2 cups of water to make rasam. So adjust accordingly.
• Add chopped tomatoes, green chilies, asafoetida and salt to taste. Cook in medium flame until the rasam mixture turns frothy
• next, add cooked and mashed dal. Mix well. Cook for 3-4 minutes.

To temper lemon rasam:

• Heat ghee in a small pan. I use my small cast iron ladle especially meant for tempering.
• Add mustard seeds and let them crackle. then, add curry leaves saute for few seconds.
• Now, add the tempering along with ghee to the prepared rasam and mix well. Add coriander leaves and remove from flame. Let the rasam cool a bit before adding lemon juice. Finally just before serving add freshly squeezed lemon juice and mix well. Serve lemon rasam hot.