Slice the butter into tablespoon sized pieces and place it in a light-colored skillet (or saucepan).
Place the skillet over medium-low heat until the butter is completely melted.
Continue cooking, stirring the butter often with a rubber spatula. Once the butter is melted it will start to bubble/sputter, then become foamy. After that, small bits of milk solids will fall to the bottom of the pan, then quickly start to brown. The butter is browned once you see these brown bits of milk solids on the bottom of the pan and smell a nutty-aroma. If needed, you can increase the heat to medium to speed up the browning process.
Immediately remove the skillet from the heat and pour the butter into a heat-proof dish. Make sure to scrape out all of the browned bits from the bottom of the pan as well, this is where all of the flavor is at!