In this recipe we use both fresh tomatoes and tomato paste. I like the taste of canned tomatoes more than that of fresh tomatoes (they actually have more taste because they are vine ripened, fresh tomatoes are ripened in transit). You know you can peel the tomatoes by putting them in cooked water for 15 seconds. Remove the seeds as well (unless you like them).
Never use an aluminium cooking pot when cooking tomatoes, high acidic food reacts with aluminium.
Heat the oil in a large skillet over high heat.
Sauté the onions in oil for 1 minute.
Stir in garlic, tomatoes, tomato paste, Italian seasoning.
Season with salt and pepper to taste.
Bring to a boil and simmer, stirring occasionally, forabout 5 minutes.
Reduce the heat to low and stir in butter pieces.
When the butter is half melted, remove the skillet from heat and continue stirring until thoroughly incorporated.