Penne Pasta with Vodka Sauce

1 pound penne pasta
2 Tablespoons olive oil
2 Tablespoons butter
1 whole medium onion, chopped finely
2 to 3 cloves garlic, chopped
3/4 to 1 cup vodka
1 can (about 14 ounces) tomato puree
1 cup heavy cream
1/2 teaspoon red pepper flakes
1/4 to 1/2 teaspoon salt
Freshly ground black pepper, to taste
1 cup grated parmesan cheese, plus more to serve

Cook the pasta according to package directions, being careful not to overcook. 1 In a large skillet over medium heat, add the olive oil and butter. When the butter is melted, add in the chopped onion and garlic. Stir and allow to cook for two minutes. Pour in the vodka. Stir and cook for three minutes. Add in the tomato puree and stir.

Reduce the heat to low and stir in the cream. Allow to simmer, being careful not to overheat. Stir in the red pepper flakes, salt, and pepper.

Drain the pasta, reserving 1 cup of pasta water in case the sauce is too thick. Add the cooked pasta to the sauce, tossing to combine. Splash in a little water if it needs it. Stir in the parmesan cheese. Pour the mixture into large serving bowl. Sprinkle with more parmesan cheese.