Heat 3 tablespoons of the reserved onion oil in a large Dutch oven over medium heat. Add the cinnamon stick, cumin seeds and the remaining 4 cloves, 4 cardamom pods and 2 bay leaves. Cook, stirring frequently, until the spices are very fragrant and beginning to brown, about 1 minute. Add the ginger and garlic and cook, stirring frequently, until very fragrant and beginning to stick to the bottom of the pan, about 1 minute. Add the tomatoes and 1 teaspoon salt and cook, stirring occasionally and scraping the garlic and ginger from the bottom of the pan, until the tomatoes start to break down and most of the liquid has evaporated, 5 to 7 minutes. Stir in 1/2 cup water, bring to a boil and scrape up any bits from the bottom of the pan.