Place onion, garlic, chilli and olive oil into TM bowl and chop 5 seconds / speed 5
Scrape around bowl, then sauté 5 minutes / Veroma / speed 1 / MC off
Add rest of ingredients, except basil leaves if using, and cook 20 minutes / 100 / speed 1 / MC on
Taste and add a little more salt if needed and cook 5 minutes / 100 / speed 1 / MC on
Place basil leaves, if using, into the base of a Thermoserver, pour over sauce, stir through and allow to sit for 5 minutes
If you are not using basil leaves, serve sauce as desired
Keeps well in the fridge for up to a week, or can be frozen for future use