Rinse tomatoes under running water and dice them. Puree them in a blender.
Heat oil in a pot and add finely chopped garlic. Saute for 1 to 2 minutes until garlic becomes aromatic.
Then add red chilli flakes if using and give a quick mix.
Pour the tomato puree and stir. Cover immediately and cook on a medium to low heat until the sauce thickens slightly. This takes about 15 mins.
Stir in between to prevent the tomatoes from burning. Be careful as the sauce splashes. You may turn down the heat and stir.
Then add salt, sugar, oregano, black pepper and basil. Mix and continue to cook for another 5 mins, until the sauce becomes thick. When it is done you will see traces of oil on the sides and top.
Turn off and add more salt if needed. Cool this completely and store in an air tight glass jar.
Pizza sauce keeps good in the refrigerator for 2 weeks and for 3 months when frozen.