Wash the arugula to control the moisture. This product in the soap tablets is arugula, which is a bit bitter to eat.
Cut the two tomatoes in half and go to the bowl with the tuna and cheese.
Making vinaigrette: Extra virgin olive oil and grape vinegar 1:1. If you don't like acid, you should put less vinegar. Add the freshly ground sea salt and black pepper, stir well with a small spoon, and sip on the salad. If you have French mustard, you can add a little.