make dressing by placing all ingredients in a bowl and whisking with a fork or whisk, till smooth.
Put the cooked rice in a large, glass salad bowl and spoon in half of the dressing.
Add chopped parsley, stir well and set aside.
Cut the pepper in half, remove seeds and pith, then place the halves, cut side down in a small roasting pan.
Add onion rings, sprinkle onion with a little olive oil, place the pan under a broiler and cook for 5-6 minutes till pepper blackens and blisters and onion turns golden. You may need to stir the onion so that it cooks evenly.
Stir onion in with rice. Put the pepper in a plastic bag and knot the bag. When the steam has loosened the skin on the pepper halves and they are cool enough to handle, peel them and cut into thin strips.
Cook the green beans in boiling water for 2 minutes, then add the corn and cook for 1-2 ninutes more, till tender. Drain vegetables, refresh under cold water and drain again.
Place in a large mixing bowl and add pepper strips, eggs and ham, if using.
Peel the avocado, remove the pit and cut into slices or chunks. Sprinkle with lemon juice.
Put the salad greens in a separate bowl, add the avocado and mix lightly. Arrange the salad leaves and avocado on top of the rice.
Stir in about 3 T of the dressing into the green bean mixture. Pile on top of salad.
Sprinkle the capers and olives on top and serve with remaining dressing.