first start washing the leaves in running water, arugula, watercress, lettuce and tomato too. After washing, put it in a solution with a liter of water and a spoonful of baking soda for 20 minutes, this will help to remove some pesticides. Then wash in running water
Grate the carrot in a coarse grater, cut the cucumber, removing the skin and cutting it very thin, do the same with the onion rings
In a bowl, arrange your salad, start with the leaves, tear the leaves with your hands, place in the bottom and the other ingredients on top, serve your salad with olive oil