Cook toor dhal in a pressure cooker with some water, turmeric, one green chilly and sliced onion.
Grind grated coconut, garlic and aniseed to a smooth paste and add this to the cooked dhal.
Add tomatoes and some water to the dhal mixture. Add required salt and cook for a few minutes until boiling starts. Remove from fire.
Heat oil in a pan and splutter mustard seeds. Add slit green chilly, chopped onion and curry leaves. Saute for sometime until the onion turns golden brown.
Pour the cooked dhal mixture into the pan and stir well. Remove from fire. Garnish with coriander leaves.