1. To a blender / food processor, add onion, tomato, garlic, chili.
2. Grind to a smooth puree.
3. Heat oil in a pan.
4. Add the puree to the oil and mix well.
5. Stir and cook for 3-4 minutes.
6. Cover and cook for 8 minutes.
7. Open the lid and stir every 1-2 minutes to avoid the sauce from sticking to the pan. Cook till the raw tomato smell no longer persists.
8. Add water, vegetable stock and mix well.
9. Add salt, sugar, ground black pepper and other spices and mix well. Taste and adjust for seasoning.
10. Continue to cook the sauce for 3-4 minutes after the spices have been added.
11. Switch off the flame. Use as required.

To Store

1. Store in an air tight container in the fridge for up to 1 week. Reheat before serving