2) Place a heavy-bottomed sautoir or pan on medium-high flame. Add the olive oil and the butter. When the butter melts and becomes foamy, add the chopped onions. Let onions saute until crispy and do not let them brown.
3) Add the diced ham, mix it in, lower the flame and let it sweat for about 15 minutes, stirring occasionally.
4) Add the tomato sauce, mix in and let simmer for another 20 minutes, then add the parsley. Simmer for 3 minutes, add the reduced double cream and the vodka, mix well and let simmer for 20 minutes
5) Check the consistency of the sauce, simmer for other 10 minutes if you need to, season and mix in the cooked penne. Let pasta simmer for 2 minutes and serve hot.
1) In a pasta-cooker or a soup pot, add 5 litres of salted water and place over medium-high flame. Bring the water to a boil, add the penne at once, lower the flame to medium, partially cover the pot and let it cook for about 11 minutes, stirring occasionally. Drain.