In a pan heat butter or oil and add the onions and sauté until golden. Add the ginger and garlic and fry for about a minute.
Add the spices and mix well. Add the tomato puree and sugar.
Stir and continue to cook on low heat for about 6-7 minutes.
Add water, bring to a boil and reduce the heat. Let it simmer for a about 5 minutes.Blend into a smooth paste.Pour the mixture into the same pan.
Add the cream. Turn off the heat. Mix well and check the seasonings.