Melt butter in a skillet over medium heat. When the butter begins to bubble slightly, add minced garlic and stir for 1 minute.
After 1 minute, add the chopped sage to the garlic butter sauce. Continue stirring for 1 to 2 minutes more, until the butter darkens to a light brown color and gives off a rich, nutty aroma.
Remove from the heat as soon as it starts to brown.
Add pre-cooked ricotta and spinach ravioli in this sauce; serve and enjoy.