Bring a large pot of salted water to a boil. This will be used to cook the pasta.
In a deep sauté pan or dutch oven, add a large drizzle of olive oil. Once it is hot, add the chicken and sauté until tender over a medium to high flame. It does not need to be fully cooked as it will continue cooking in the sauce later.
Add in the garlic and onion and sauté for about three minutes.
Lower the flame to medium/low and pour in the vodka. Raise the flame again to medium and cook for about three minutes to allow the alcohol to evaporate. The vodka amplifies the flavor of the sauce while also helping to keep the heavy cream from separating when added to the tomato sauce.
Raise the flame to medium/high and pour in the tomato passata. Mix together and bring to a boil. Once boiling, reduce to a simmer and allow to cook for at least ten minutes.
Meanwhile, add the penne into the pot of boiling water. Cook the pasta for one to two minutes less than the package instructions or al dente.
Two minutes before the pasta is ready, taste the sauce and season with salt and black pepper if needed. Pour the heavy cream into the sauce pan and mix together.
Once the penne is ready, use a hand strainer to scoop it directly into the vodka sauce dutch oven/pan. Mix together and allow to finish cooking for another two minutes in the pan.
Remove from the pan and serve with a sprinkle of freshly chopped parsley and pecorino cheese. Salute and cin cin!