In a medium pot, bring water to boil. Add the gnocchi and cook according to the package instructions. Drain and set aside.
While the gnocchi is cooking, melt the butter in a large non-stick skillet over medium high heat. Add the mushrooms and cook for about 5 minutes, letting them brown nicely. Add garlic and rosemary and cook for another minute.
Add wine and cook for 3-4 minutes, until the wine is almost evaporated but there is still some liquid remaining. Add the gnocchi, stir everything gently and keep cooking for 5-7 minutes until the gnocchi brown slightly.
Remove pan from the heat and sprinkle feta cheese on top. Garnish the dish with some fresh chopped parsley. Enjoy!