Everyone enjoyed this except DH, who doesn't like olives so he doesn't count anyway. I substituted ordinary, chunk light tuna and had to use dried basil but even so the flavor was wonderful. I used my homemade Italian dressing -- a very simple vinegrette of red wine vinegar, extra-virgin olive oil, garlic powder, and Italian seasoning. The only things we'd change is to first, tone down the very assertive onion taste by either cutting down to just a tbs or using vidalia instead of red, and second, double up the celery. Adding some more green stuff such as spinach, escarole, curly endive, or even dandelion greens would probably improve it even more. This and a supply of crackers would be a great for potlucks with no mayo to get all soggy while it sits.