Bring a large pot of water, along with 2 tbsp. kosher salt, to boil.
Heat a large pan to medium heat; add in the olive oil and sausage.
Brown the sausage around 5 to 7 minutes; make room in the pan and add the mushrooms; continue to cook until they brown.
Once the sausage and mushrooms are brown, add the onion and garlic.
After 2 minutes, remove the garlic from the pan and discard.
Continue cooking for a few more minutes until the onions are soft.
Turn heat to medium-high and add the wine; cook for a minute to reduce the wine by about half.
Scrape the bottom of the pan, with a wooden spoon, to remove all the brown bits.
At this time, begin cooking pasta to a bit less than al dente.
Add the cream and bring sauce to a simmer while stirring.
Once simmering, turn the heat down to low.
When pasta is almost al dente, add it to the sauce; mix to coat.
Turn heat to medium; add a bit of pasta water, if needed, to loosen things up.
Continue to cook, stirring frequently, until the pasta is perfectly al dente.
Turn the heat off and remove the pan from the heat.
Add the Pecorino; mix well; taste test.
Season with a good amount of black pepper, a pinch of nutmeg and salt, to taste.
Serve with grated Pecorino.