Bring a large pot of water to a boil. Add salt and cook pasta according to directions on the package.
Reserve 2 cups of the pasta water before draining.
In a large Dutch oven or skillet over medium high heat, heat oil. Once hot, add onion and cook until softened, about 7 to 10 minutes. Stir in garlic and cook for 30 seconds, until fragrant.
Add sausage and cook until browned or cooked through, breaking it up into small pieces as you cook it. Reduce heat to medium heat, stirring in red pepper flakes.
Add wine to deglaze, scraping up any browned bits on the bottom. Stir in cream and bring mixture to a simmer. Cook for 3 minutes, stirring occasionally.
Add kale and lemon zest, cooking until the greens are wilted, about 5 minutes. Stir in salt and pepper. Taste and season with additional salt and pepper if desired.
Add cooked pasta to the Dutch oven, stirring to coat. If the sauce is too thick, add some of the reserved pasta water as needed.
Stir in Parmesan cheese and lemon juice.
Serve immediately with additional parmesan cheese.