Grate the onion finely and fry in 1 tablespoon of oil in a saucepan. Add the tomatoes and the rest of the ingredients to the saucepan and simmer. The sauce should thicken a bit.
Season to taste with the spices and let simmer a little more.
Then pour into hot-boiled glasses and screw tight.
The ketchup will keep for a few months. I always fill 3 small glasses.