Cut the onion into thin half-rings, marinate for 20 minutes in vinegar with sugar and salt.
Cut the pickled cucumber. In theory, the croutons from the bagel should be fried in vegetable oil and only then rub them with garlic. I just dried it in a dry pan and rubbed it with garlic.
Mix all the ingredients in the salad, add vegetable oil to taste. I did not add salt to the salad anymore, I had enough already. If desired, you can also add salt.