Fry the potatoes in hot oil in the pan, being careful not to stick them or make them too dark. In the meantime, peel the kohlrabi, cut into sticks and after about 10 minutes add to the potatoes in the pan. Fry everything for another 10 minutes over medium heat. Season with salt and pepper. Finally add oregano and possibly other herbs and spices.
If you want and if you like it, you can make the kohlrabi and potato pan even creamier with cream cheese. But then it is no longer vegan.