In the subcontinent, spices are tossed into hot oil at the start of cooking, or added to a dish partway through cooking, or sprinkled on at the end. Like onions or garlic or fresh herbs, they’re designed to heighten or deepen flavor, not to mask it. The whole and ground spices used early on (such as mustard seed or the Bengali Five-Spice Mixture) flavor the cooking oil and give the kitchen an appetizing aroma. Then they are joined in the oil by moist ingredients such as garlic, green chiles, and/or ginger or, in southern India and Sri Lanka, curry leaves, which also need to cook in the oil to release their flavors and aroma. Later, as the dish simmers, whole spices such as cinnamon sticks or bay leaves or dried red chiles may go in to flavor the broth.