Wash the tomato and using knife make slice a shallow “X” in the bottom of each tomato.
In a deep pan with high heat boil 2 liter water. Then gently put all tomatoes in the boiling water and simmer for 1 minute. Remove them and dunk them in cold/icy water. This will make them easy to peel. Using the slit, peel off all the skins, and then chop up the tomatoes.
Heat olive oil over medium heat in a large saucepan. Add garlic, onion and cook, stirring, until softened and fragrant but not browned, about 2 minutes. Add pepper flakes and oregano and cook, stirring, until fragrant, about 1 minute. Add tomatoes, sugar, parsley and basil, and stir to combine. Season lightly with salt and pepper. Bring to a simmer over high heat.
Turn the heat down to low, cover the pan and simmer for one hour, giving everything an occasional stir. After an hour, turn off the heat and allow the tomato mixture to cool slightly. Then blend them to as smooth a consistency as you can. After blending, pass the mixture through a strainer to get it even smoother and to get rid of any seeds.
Put the strained mixture back into the pan. Add vinegar, food color and Simmer on low heat while stirring until the tomato ketchup thickens slightly. Remember it will thicken a bit more as it cools.
Let the sauce cool and then transfer it into freezer containers or freezer bags. Sauce can be kept frozen for at least three months before starting to develop freezer burn or off-flavors.