I often use clarified butter, aka ghee, as a way to reduce the lactose content of butter. Clarifying butter helps remove water, lactose and casein leaving you with luscious butterfat that can be used at higher temperatures than you would normally use with butter. The web site “the kitchen” gives step by step instructions on how to make your own. I sometimes buy ghee locally, but it is pricey. If you use ghee frequently in your cooking, it makes sense to make your own.