Bring a large pot of salted water to a boil. Add the gnocchi and cook according to package instructions until they float to the surface, usually about 2-3 minutes. Drain and set aside.
In a large skillet, melt the butter over medium heat. Continue to cook, stirring frequently, until the butter turns golden brown and develops a nutty aroma, about 5-7 minutes.
Add the minced garlic and sage leaves to the browned butter. Sauté for an additional 1-2 minutes until the sage becomes crispy and fragrant.
Gently add the cooked gnocchi to the skillet, tossing to coat them in the brown butter and sage mixture. Cook for another 2-3 minutes until the gnocchi are warmed through and slightly crisped.
Season with salt and pepper to taste.
Serve hot, garnished with a sprinkle of grated Parmesan cheese and toasted walnuts for an added crunch.