Heat the oil and butter in a large deep saucepan.
Add the onion, capsicum and garlic and cook, stirring until it all softens. This takes about 7 minutes.
Add the tomato paste, passata and tin tomato and stir them through.
Add the rest of the ingredients, stir them through then bring the mixture to a boil.
Reduce to a simmer and simmer, stirring occasionally for 2-3 hours.
Transfer the sauce to jars and seal them.
In well-sealed jars, this sauce can keep for up to 1 year. Once opened it will only keep a few days. Alternatively, the sauce can be frozen.