Step 1

Bring the water to a boil (a kettle works well for this).

Step 2

Quarter the onions and then break them apart into petals (roughly - two or three petals per quarter)

Step 3

Combine all ingredients except tomatoes, bring to a gentle boil and simmer, loosely covered, for one hour. Use a big pot!

Step 4

Add tomatoes, stir and simmer an additional 20 minutes

Step 5

Let cool slightly. Blend to smooth consistency. Make sure you remove the centre cap from the blender lid and cover the hole with a cloth or you will be cleaning the ceiling. Alternately you can use an immersion blender.

Step 6

Wipe out the pot and return pureed curry base and simmer, loosely covered, until the oil separates out - this can take an hour or more. Stir the oil back into the base. At this point you can portion out the base into 2 cup portions and freeze if desired.