Spices represent the heart of the kitchen, giving life to the blank canvas that begins each new recipe. Spices also play an important role in maintaining health. For example, ginger and cumin aid digestion; turmeric acts as one of nature's most powerful cleansers. I have often made my own spices by simply dry-roasting cumin seeds and pounding them in my well-worn stone mortar-and-pestle until it becomes fragrant cumin powder.