DICK's GREEK SALAD
2 cucumbers -- peeled, quartered and chopped
1/2 large Vidalia onion, chopped
3/4 basket of grape tomatoes -- halved (or chop whole tomatoes)
@ a cup of whole Kalamata olives
1 bell pepper -- chopped
@ a cup of chopped Romaine lettuce
@ 1/2 cup of crumbled Feta cheese
celery salt
garlic powder
olive oil
red wine vinegar 

Greek Salad is less about lettuce and more about olives, tomatoes and cucumbers -- the quantities specified above are meant only as a guide to relative proportions.  Good olives and olive oil make a huge difference -- I use Krinos Greek olives (in jars in the olive section) or Athenos Kalamata Olives (in plastic packages in deli).
Put all the ingredients in a large bowl and toss with olive oil only to coat, sprinkle with more celery salt and garlic than you usually would, and sprinkle with vinegar