Melt 2 tablespoons butter in a large skillet over medium-high heat. Once melted, add the sausage and begin breaking it up with a wooden spoon. Cook until the sausage has browned. Transfer the sausage to a plate and set aside.

Add remaining butter, stir in onion and garlic and cook until softened, about 3 minutes. Add kale and cook, stirring often, until it begins to wilt. Season with salt, pepper, nutmeg and red pepper flakes. Stir in chicken stock and milk and bring to a simmer. Add gnocchi and stir until well combined. Cover and cook over low heat until the gnocchi are tender and almost all of the liquid has evaporated, about 5 to 8 minutes.

Uncover and stir back in the sausage, parmesan and heavy cream. Taste and adjust seasoning accordingly. Serve with parmesan and crushed red pepper flakes on top, if desired. Enjoy!