Yes, tempering spices can be done with butter instead of oil, especially when you want to impart a rich, nutty flavor to the dish. However, butter burns more easily than oil, so careful attention to heat control is crucial.
Tempering, also known as 'tadka' or 'chhonk,' is a cooking technique where whole spices are briefly heated in fat to release their essential oils and enhance their flavor. Traditionally, oil is used because it has a higher smoke point than butter, meaning it can withstand higher temperatures before burning. However, butter can be used as a substitute, offering a unique flavor profile. When using butter, it's important to use low heat and monitor it closely to prevent burning. The process involves melting the butter in a pan over low heat, then adding the whole spices (such as cumin seeds, mustard seeds, dried chilies, and curry leaves). As the spices sizzle and release their aroma, they are then added to the dish, infusing it with flavor. The milk solids in butter contribute a nutty, browned butter flavor that complements certain dishes beautifully.
To prevent butter from burning during tempering, consider using clarified butter (ghee). Ghee has had the milk solids removed, resulting in a higher smoke point and a richer, more intense flavor compared to regular butter.