Thinly slice the white cabbage using a mandoline slicer.

Cut the red bell pepper and sweet onion into cubes.

In a large bowl, add salt to the shredded cabbage and massage it with your hands until it becomes juicy.

In a small saucepan, combine vinegar, vegetable oil, and sugar.

Bring the mixture to a boil and cook until the sugar has dissolved, creating a marinade.

Pour the boiling marinade over the cabbage, bell pepper, and onion mixture.

Mix thoroughly with a spoon, and then with your hands.

Add the mustard to the mixture.

Transfer the salad to a glass container.

Cover the container and let it infuse at room temperature for one day.

Store the krautsalad in the refrigerator.