In a large skillet over medium-high heat, add the olive oil and onions. Cook the onions until they are translucent, approximately 5 minutes. While the onions are cooking, remove the sausage from its casing.
Add the sausage to the skillet by breaking it into small, bite-size pieces. Stir to combine. Cook the sausage, stirring occasionally for about 5 minutes.
Add the wine and cook for an additional 5 minutes until the wine is absorbed by the sausage and onions.
Whisk in the stock, salt, pepper, sage, and rosemary and continue to cook until the stock begins to reduce, approximately 10 minutes.
While the stock is reducing, bring a large pot of generously salted water to a boil. Add the pasta to the boiling water and allow it to cook for 7 to 8 minutes until just al-dente.
While the pasta is cooking, add the tomato puree to the sausage and stock. Bring this back up to a boil. Reduce the heat to medium-low and whisk in the cream. Allow the sauce to simmer for 3 to 4 minutes.
Using a spider or pasta scoop, place the pasta in the pan of sauce. It is okay for some of the starchy pasta water to make its way into the sauce to help thicken it. Allow this to warm through until the pasta is tender.
Remove the gramigna and sauce to a large serving bowl and generously top with the Parmigiano-Reggiano and a good drizzle of extra virgin olive oil. Serve with extra cheese on the side.