True Believer Tomato Sauce - cooking recipe

Ingredients

2 onions, skin removed and cut only in half (not diced)
2 (28 ounce) cans san marzano tomatoes (from an Italian specialty store)
1/2 cup butter

Preparation

In a large pot, pour both cans of tomatoes and heat.
Add the whole stick of butter.
As the butter starts to melt, add the onions.
Stir and bring to a boil then set the heat to low.
Cook for 1 1/2 hours.
Serving suggestion: Pour over linguini and top with fresh grated Parmesan cheese.