Clean, core and peel all the vegetables first, as needed, and only then weigh them.
Cut tomatoes and peppers into small cubes, grate carrots coarsely and chop onions finely.
Put the vegetables in a saucepan, add salt and heat slowly over low heat, stirring, for about 5 - 10 minutes until there is enough vegetable juice.
Bring the vegetables to a boil and simmer with the lid on for about 25 minutes until tender.
Add vegetable oil to the vegetables, stir and cook for another 5 minutes.
Immediately pour the hot vegetable salad into sterilized preserving jars to the top, seal them, place them on the lids and cover them with a large towel or something similar.
Let the vegetable salad cool like this overnight, then turn the jars and place them in a cool and dark place.