Creamy Vodka Sauce

Here is the recipe my sister emailed. I added minced garlic with the onions--several cloves, maybe 5 or 6. And I grated the parmesan fresh.

1 quart heavy whipping cream
1 large can of whole peeled tomatoes - don't drain
1 large can of diced tomatoes - don't drain
3/4 cup vodka
1 cup parmesan cheese
1 onion chopped and sautéed in butter
salt and pepper to taste

Sauté onions and then put all ingredients, including onions, in a large pot or crock pot and cook over low heat. Simmer, stirring occasionally. Serve over pasta.