Put the tomato paste in a saucepan. Season with vinegar, sugar, salt and pepper. Boil for 15 minutes. Careful not to get burnt as the tomato splashes easily when hot.
Peel and chop the onion as finely as you can. Also chop the bell pepper and jalapenos into very fine cubes.
Once the tomato paste has boiled, add the vegetables and leave the salsa sauce to cool for a while.