Prepare your mise en place and set aside. Pour tomatoes into a blender/processor and process for a few seconds until a thick sauce is formed.

Heat olive oil in a large pot over medium heat. Add chopped onion and about half of the parsley. Sauté for about 6-8 minutes or until onion becomes slightly translucent. Add minced garlic and cook for a few minutes longer being careful not to burn the garlic. Then add tomato paste and cook for a few more seconds.

Add pureed tomatoes to pot along with the remainder of ingredients. Stir to combine, cover halfway with lid and simmer on low for 45 minutes, stirring frequently throughout the cooking process as it thickens. The sauce can be stored in the fridge for up to a week or in the freezer for up to four months.