First, prep all the ingredients before starting.
In a large pot, cook the sausage first then remove from the pot. Now, toss in the onion and garlic on a medium high heat. If the bottom is dry add a little oil.
Cook until browning and fragrant. At that point lower the heat to medium and toss in the butter. Allow the flour to mix with everything and bubble.
Next, add in the sausage back in and pour in the broth. Bring the soup to a simmer and add in the kale and the gnocchi.
Both of those ingredients will be ready in less than 5 minutes. Then, you can turn off the heat.
Lastly, add in the heavy cream and add salt and pepper to taste.