Heat a very small amount of olive oil in a pan, and wait until hot.
Finely slice or chop your garlic and add it to the pan. Don’t let the garlic get too brown (burnt garlic is not good). If you are adding chopped chilli, add this now too.
Fairly quickly, add the tin / tins tomatoes; the thyme and/or oregano (dried or fresh) and some salt and pepper.
Gently cook until nearly all the liquid has reduced away from the sauce. It should be really thick, sweet and tasty. This takes around 15 minutes or so – if you want the sauce to be sweeter, add more water and reduce down again.
This sauce has lots of brilliant applications – you can eat it with virtually anything but is particularly good with potatoes (patatas bravas) and pasta and makes a great pizza sauce too.