Take a 1/4 of a medium red cabbage and chop it. If your red cabbage is really small, maybe you'll need 1/2 of it. Put chopped cabbage into a bowl and salt. Now you need to squeeze cabbage in the bowl with your arms to soften it. Do it till the cabbage is quite soft.
Chop the onion into small pieces, add to cabbage, add a table spoon of sugar, mix the salad. Now pour 1 table spoon of vinegar(I usually use the ordinary one or apple vinegar, with the second the taste is a little more gentle) and 2 table spoons of oil(I prefer sunflower or olive oil). Mix the salad so all cabage covered with oil and vinegar. Let rest for 2-5 min so that salad can become more juicy and enjoy your meal!