Heat 1 tbsp oil in a wok/kadai.
Add the curry leaves and red chilies. Saute for a few seconds.
Add the onions and saute till they turn light brown.
Now, add the tomatoes and saute till the tomatoes are semi cooked. Remove from fire and let the mixture cool.
Grind the mixture in the big jar of the mixer grinder to a smooth paste.
:- need not add any water since the tomatoes will release enough water while grinding.
Heat remaining oil in a kadai.
Pour in the ground mixture.
Pour half a cup of water into the mixie jar and pour the chutney stuck to the jar into the kadai.
Cook covered, till oil separates.
:- the thuvayal will splash while cooking, so take care.
Serve hot with idli, dosa, masala paniyaram or rice.
Happy Cooking :)