Add cumin seeds, cardamom pods, bay leaves and cinnamon sticks to the pan and cook, for about 45 seconds. Add
the sliced onion and cook, stirring, until light brown, about 2-
3 minutes. Carefully pour in the pureed tomato mixture and reduce heat to medium. Stir in garam masala, 3/4 teaspoon salt and turmeric. Simmer, partially covered, stirring occasionally, until most of the liquid evaporates, about 15 minutes.