Heat the olive oil in a large saucepan over medium heat. Add the garlic and cook, stirring frequently, until it just turns golden, 3 to 4 minutes. Add the tomatoes, Italian seasoning, basil, 1 teaspoon salt and a few grinds of fresh pepper. Bring to a simmer and cook, stirring occasionally, for 7 minutes. Take off the heat and stir in the butter until melted. Add salt and pepper to taste.