The famous LENTIL SALAD

What ingredients do I need for this lentil salad?
Cooked lentils, 250 g (one cup).
One medium eggplant.
1/2 red pepper.
Black or green olives.
Olive oil.
Cumin.
Grain mustard (old mustard)
Apple cider vinegar or whatever vinegar you use.

The consumption of lentils and fresh vegetables is beneficial due to the high content of iron and vitamins.