Wash the lettuce and drain well. Quarter the tomatoes and remove the stalk if necessary. Cut the feta cheese into cubes. Halve the pitted olives and drain together with the corn. Now put the lettuce, tomatoes, feta cheese, olives and corn in a large bowl. For the dressing, put the remaining ingredients in a blender (or work with a blender) and mix well. Put the dressing in the bowl and mix everything well.