Peel the onion and dice into small pieces.
In a medium sauce pot, melt butter. Saute onion with a pinch of salt in the butter until the onion is translucent; add garlic and cook just until beginning to turn light brown.
Add cream and bring to a low simmer. Stir constantly to reduce the volume of cream by half.
Add Carbone Tomato Basil Sauce to the cream mixture and bring to a simmer, stirring constantly.
Add salt and pepper to taste.
Once heated through, pour into bowls and garnish with Parmesan cheese and/or basil leaves.