In boiling water, pour the lentils, cook over low heat with the lid closed for 25 minutes, at the end of cooking, add salt.
Prepare the dressing: mix balsamic vinegar, olive oil, lemon juice, ginger (if fresh-grate on a fine grater) and black pepper.
Wash and dry the arugula.
Cut the cherry and olives in half.
Cut the feta into small cubes.
Gently mix the lentils with the feta cheese, tomatoes and olives. Put the arugula on a platter, put the salad on top and pour the dressing over it.