In a large pot over medium heat, brown kielbasa and onion.
Add milk, broth, and pasta to the pot along with the sausage and onion. Stir in the cornstarch and seasonings and bring to a boil.
Once boiling, reduce the heat to a simmer and cover, and cook for 10-16 minutes or until the pasta is tender. Check the pan frequently and add more water or broth as needed.
Once the pasta is tender, remove the pot from the heat. Remove kielbasa from the pot and slice.
Stir the cheese into the pasta until melted. Stir in the sliced kielbasa and serve.