For making Urundai:
Soak the toor dal for at least 2 hours, drain the water and take the dal with red chillies, fennel seeds and salt. Grind to a coarse paste.
Add the onions, garlic, grated coconut, curry leaves, mix well and make small balls out of them.
Now you can steam cook balls in 10 minutes. But I dropped them directly while cooking the gravy.
For making gravy:
Grind all the ingredients given above the list to grind as fine paste and keep aside.
Heat enough oil, let it splutter along with the mustard seeds and fennel seeds.
Add in the curry leaves and fry. Now add the garlic, onions stir fry for few minutes and add the tomatoes and cook until they turn mushy.
Now add the grounded paste and cook on simmer 10-15 minutes or until the oil separates.
Add 2-3 cups of water, bring it to a boil. Put the flame on simmer and add the toor dal balls to the cooking gravy.
cover the vessel with the lid and cook on simmer for at least 10 minutes or until the dal balls gets cooked.
If the gravy is thick, you can add water as per need.
Ready to Serve immediately with rice.