Cut the chicken into strips. Chop the onion, tomatoes and arugula into small pieces. Add a little oil from the pickled tomatoes to the pan and fry the chicken and onion in it. As soon as the chicken is done, add the tomatoes and roast them again briefly. Now sprinkle the meat and tomatoes with cornstarch, stir and add the cream. Depending on whether you like it a little creamier or more liquid, you can play with the amount of cornstarch or add a little water. Now season the sauce with salt and pepper and bring to the boil briefly. The rocket is added shortly before the end. How much you take depends on personal taste. The rocket collapses a lot when it gets into the sauce.