Fry the onions in the oil until they are translucent, but not browned.
Add the garlic and fry for another minute.
Add the tomato, as well as any tomato juice you can preserve. Let the tomatoes fry in the pan until most of the juice has reduced.
Add salt and pepper to taste, as well as the vinegar, sugar and tomato puree. Let the mixture come to a simmer.
At this stage, the mixture will probably resemble a wet stir-fry. Add ½ a cup of water, or as much as you need to create a saucy consistency.
Let the sauce cook on medium heat, stirring occasionally until most of the tomato pieces has broken down and the sauce has thickened (around 20 minutes). Add the chopped herbs 5 minutes before serving.
Check the seasoning adding more salt or sugar if needed. Serve on pap of your choice as a side dish to some delicious braaied Boerewors.