Clean, wash and wipe tomatoes well
Trim from the top, make a slit on each tomatoes and put them in large heavy bottom pan
Add 2 tablespoon of olive oil, mix. Cover and simmer for an hour. Stir few times in between
After an hour, cool it slightly and carefully take off the peels from the tomatoes. Mash it lightly
In another heavy bottom pan, heat 1 tablespoon of oil and 2 tablespoon of butter.
Add crushed garlic and fry for few seconds until it releases aroma.
Add chopped onions and fry until soft and pink
Add cooked tomatoes and mix well. Cook on high heat for 2-3 minutes
Add chili flakes, salt and pepper, oregano and mix well
Add roughly torn basil and mix
Cover and simmer for another 30 minutes.
Add sugar, vinegar and mix.
Cook for another 5 minutes.
If you prefer your sauce to be smooth, blend in blender.
Cool it completely.
Store it in a clean sterilised jar and refrigerate easily upto 2 weeks.