Use a hand blender to gently blend the peeled tomatoes directly in the can. Then set aside.
Chop the onion, celery, and carrots into small pieces then add them to a blender.
Pour in 7-8 tablespoons of EVOO, and add a splash of water. Blend until creamy and add another drizzle of oil if it is too thick and chunky.
Heat a cast iron pot over medium heat and add 2 tablespoons of EVOO. Add the blended vegetable mixture, stir, cover, and let it cook for 10 minutes.
After 3 minutes, check the mixture. If it seems dry, add a splash of water and stir to combine.
Once it has been cooking for 10 minutes, add the blended tomatoes and stir well using a wooden spoon.
Cover and let simmer for 1 hour. Give it a stir every 10-20 minutes to ensure even cooking and prevent it from sticking to the bottom.
After 1 hour, remove the lid, stir again,season with salt and pepper then stir once more.
Take the pot off the stove, tear the basil leaves by hand, add them to the pot, and give it a final mix to infuse the basil flavour.