• Dice and blend onion, ginger, ginger, chillies to a fine paste.
• Heat oil in a pan. Once oil is hot add the onion paste to it. Mix well and saute.
• Saute till onion gets cooked and leaves oil on surface.
• Add coriander powder, red chilli powder, turmeric powder, cumin powder, black pepper powder, salt.
• Stir and mix them well.
• Add 1/4 cup water and cook on low flame.
• Cook till it leaves oil from surroundings.
• Gradually it will be thicker.
• Keep on stirring periodically.
• Turn off the gas and let it cool completely.
• Then transfer to an air tight container and store in refrigerator.

Using Tomato Puree

• Blend tomatoes to puree.
• Steps will be same as point 6 above.
• Once mix of onion paste and ground spices are cooked, add tomato puree.
• Give it a nice stir.
• Cook again till the mixture becomes thick and leaves oils on sides.
• If required cover with a lid and cook on medium to high heat.
• When it's cooked and thick, turn off heat.
• Cool completely and store in airtight jar.