In a large dutch oven or stock pot, heat the oil over medium high. Add the sausage, fennel seeds, and red pepper flakes and brown, breaking the sausage apart with wooden spoon. Add the onion and garlic and cook, stirring often, for about 5 minutes or until softened.
Add the chicken stock, water, tomatoes, Italian seasoning, kosher salt and pepper. Bring to a boil then simmer for 10 minutes. Add the gnocchi and cook until they float to the top, about 5 minutes. Turn off the heat, stir in the spinach and taste for seasoning. Serve hot with a sprinkling of Parmesan cheese.
