My Nonna makes her tomato sauce like this:
Put a good slug of olive oil in a pot, add a chopped onion, chopped chilli and a clove of crushed garlic. Fry for around 5 mins on a med heat until translucent. Add 2 tins of peeled plum tomatoes and a bottle of passata. Allow to come to the boil and simmer for 2 hours. Season and add fresh basil. This will make enough for 4 portions so any you don't need you can freeze.
To make the creamy sauce:
In a frying pan fry some garlic and 1 chilli(more if you want it hotter) together, fry for around 5 mins on a med heat. Add a splash of white wine and cook out the alcohol. Add a couple of ladles of the tomato sauce, heat through. Add some double cream and bring to a simmer. Season and pour over chicken or fish and you can also use it stirred through cooked pasta.
I don't know if that is the exact one you had but that is how my Nonna in Italy makes hers. Enjoy!