Drain the excess liquid from the corn. Cut the olives into slices.
Chop the spinach and cut the tomatoes into half rings or cubes. Whatever you like. Drain the liquid from the tuna and remove the central bone. Break it into random pieces.
For dressing: mix oil, soy sauce and lemon juice. If desired, add a pinch of salt and ground pepper. Mix it. Season the salad and mix it gently.
