Cook pasta according to package directions.
Add olive oil in a sauce pan and make sure it is fully coated.
Add red onions, garlic cloves, and tomato paste and stir.
Add cajun seasoning.
Add the heavy cream and stir.
Add the pasta water and stir.
Fold in 3 cups of farfalle pasta, and sprinkle with Parmesan cheese.
Stir in the fresh basil and butter.