Make a fine paste of grated coconut, turmeric powder and red chilli powder.
Add 1 tbsp water (very little water) when making the paste and keep aside.
In a pan, heat oil and add finely chopped onions and fry till golden brown and crisp on a low to medium heat.
Add tomato pieces and salt to taste. Do not add water.
Cover with a lid and cook on a low to medium heat for 8 -10 minutes or until the tomatoes soften.
Add coconut paste, stir well (adjust with 2 - 3 tbsps of extra water if you require) and cook again for 5 minutes on a low heat or until the tomatoes are well blended with coconut paste / fragrant (gravy is medium thick in consistency).
Serve as a side dish with dosa (polo) / rotis / rice.
Heat oil in a frying pan add mustard seeds.
When they splutter, add jeera, methi and fry for 1 - 2 minutes or until fragrant.
Add curry leaves and saute for 2 - 3 minutes until fragrant.
Pour the seasoning over tomato santosh and mix well. Serve with rice.