In a large pot over medium heat, add 1 tbsp of olive oil and then brown the Italian sausage. Remove and set to the side.
In the same pot, add 2 more tbsp of olive oil and then sautée the chopped leek, shallot and garlic. Season with salt and pepper and stir for another 4-5 minutes until slightly softened.
Deglaze with the white wine and stir for another few minutes. Add the crushed tomatoes, the stock, and then bring up to a bubble. Reduce the heat and simmer for 20-30 minutes, partially covered.
Add in the gnocchi and continue to cook for a few minutes until the gnocchi are tender. Add in the cup of cream, stir, the Italian sausage goes back in, and then a couple handfuls (or however much you like) of spinach. It will wilt quite quickly so I highly recommend serving soon after the spinach goes in!
Ladle into a bowl and garnish with lots of shaved parmesan, some red pepper flakes for a bit of a kick, and some cracked black pepper.