Melt the butter in a large skillet over low heat. Add the shallot and chopped sage and cook over low heat for 4-5 minutes, being careful not to burn. Add the gnocchi and continue, stirring occasionally for an additional 4-5 minutes. Let the gnocchi brown slightly. Add the stock and increase heat to medium. Continue cooking until most of the stock has evaporated and the gnocchi is hot, about 4-5 minutes.
Divide among 6-8 bowls and finish each with shredded cheese as desired.