Fry the onions in the oil on a medium heat for about 5 minutes until the onions are soft and translucent.

Add the garlic and ginger then sauté for 1 minute.

Now add the Passata and cook for a further 3 minutes.

Now add half the water and simmer for 5 minutes, stirring well.

Add the remaining spices and water and cook for another 5 minutes.

Remove from heat and allow the sauce to cool down.

Purée the sauce in a food processor then store or use.