Use this recipe to make Potato Galettes and Rosti Potatoes. Because this butter has no milk solids, it can withstand higher cooking temperatures without burning.
Melt butter in a small saucepan over low heat until foamy and milk solids have fallen to bottom of pan, about 15 minutes. Remove from heat, and let cool.
Carefully skim foam from top, and discard. Slowly pour liquid butter into a bowl or storage container, leaving the solids behind. Use immediately, or keep covered in refrigerator up to 1 month.