This is largely from Craig Claiborne's The New York Times Cookbook, a really great cookbook. I don't know the copyright implications of posting this, but if you're from the legal department of Harper & Row, please just consider this one big advertisement for the book.

Here's the recipe, with my own comments and variations interspersed throughout. It's really just about the perfect summertime dish, IMHO.

6 to 10 servings

2 teaspoons mustard, preferably Dijon
2 tablespoons wine vinegar (I substitute wine; rice vinegar also works fine)
1 1/2 teaspoons salt
1 or 2 garlic cloves, minced
6 tablespoons peanut or vegetable oil (I use extra light olive oil)
6 tablespoons extra virgin olive oil (he just says OO, I use EVOO)
Freshly ground pepper to taste (don't skimp, it needs to cover a lot food)
1 teaspoon chopped fresh thyme, or 1/2 teaspoon dried (works well either way)

2 pounds green beans
2 green peppers
4 celery stalks, approximately (I usually end up using 5)
1 pint cherry tomatoes (I use 5-6 romas)
5 medium red skinned potatoes, cooked, peeled and sliced (I leave the peel on; looks better)
3 cans (6 or 7 oz) of albacore tuna
1 2 oz. can flat anchovies
10 stuffed olives (I just use 10 plump green olives, cut in a variety of sizes)
10 black olives (I use Kalamata, again, cut in a variety of sizes)
2 small red onions (he suggests 1 lg or 2 small; large onions yield unwieldy rings IMO)
2 tablespoons chopped basil or 1 teaspoon dried (I'd be reluctant to use anything but fresh basil)
1/3 cup finely chopped parsley
1/4 cup finely chopped scallions
6 hard boiled eggs, quartered lengthwise

1. Start by beginning to boil the eggs and potatoes. Also start a large pot of salted water boiling for cooking the green beans. Reserve the hot water from one of the pots and use it for blanching the tomatoes. (This is my own added step. He considers this implied from the ingredients list.)

2. In a mixing bowl, combine the mustard, vinegar (again, I substitute wine), salt, garlic, extra light and extra virgin olive oils, pepper and thyme. Beat with a fork until well blended and set aside.

3. Pick over the beans and break or cut them into 1 1/2 inch lengths. Place in a saucepan and cook in salted water to cover until tender but crisp. (I bring the water to a boil and add them. I watch them like a hawk. Generally, within a minute or two of they're becoming bright green, they're ready. Doesn't take long. You can also notice when they're ready if you eat them: the moment they're not obviously raw when tasted, take them out -- they're perfect.) Drain and run under cold water, then drain in a colander and set aside. (It's pretty important to run them under cold water until they're cold, of course, otherwise they'll continue cooking and get soft.)

4. Remove the cores, seeds and white membranes from the green peppers. Cut the peppers into thin rounds and set aside. (Perfect job for a mandoline, if you have one. With a knife, just cut them as thin as you can. With a mandoline, I like 'em at about two mm.)

5. Trim the celery stalks and cut crosswise into thin slices. There should be about 2 cups of sliced celery. Set aside. (Again, the thinner the better, IMHO.)

6. Blanch the tomatoes one at a time in boiling water for exactly 15 seconds, no longer, or they'll become mushy. Drain immediately. Using a paring knife, pull off the tomato skins. (The NYT Cookbook has you set the cherry tomatoes aside. Now's the time I usually quarter the peeled romas and seed them.)

7. In a large salad bowl, make a more or less symmetrical pattern of the green beans, peppers, celery, tomatoes and potatoes. Flake the tuna and add to the bowl. Arrange the anchovies on top and scatter the olives over all. (I skip this entirely, continuing on to prep the onions, basil, parsley and scallions and then mix everything together in a big bowl or in a very large pot. The only thing I arrange carefully on it are the quartered boiled eggs. Once, I reserved the tomatoes and spread them around. My basic advice here is: mix it all up really well and then serve it. There's too much salad to toss it in any ordinary serving bowl. Easier just to prepare it completely before presenting.)

8. Peel the onions and cut into thin, almost transparent slices (I like to cut the onions in half and then slice them into half-rings. Whole rings can get a little unmanageable to eat.) Scatter the onion rings over all. Sprinkle with basil, parsley and scallions. Garnish with hard-boiled eggs.

9. Toss the salad with the dressing after the garnished bowl has been presented to the guests for their enjoyment. Serve with a crusty loaf of French or Italian bread.

More of my own notes:

The wine vinegar: I substitute dry wine because vinegar seems to clash with wine, which I usually serve with this dish. I've used both whites and reds with good results. I've only used acidic reds, though, not tannic ones.

The salt in the dressing: the dressing will taste salty, but it's spread out over a _lot_ of vegetables, so I'd suggest resisting the temptation to skimp on the salt. Nobody has ever noticed the level of salt.

The tomatoes: cherry tomatoes are a pain to peel, but the salad does best if the tomatoes are peeled. Romas are easy to seed and peel, so that's what I always use. I usually chop them into large pieces or quarter them lengthwise, and then seed them, too.

The tuna: the NYT Cookbook recipe doesn't call for it, but I always use albacore. It holds up better and has a more subtle flavor. I've been meaning to grill some tuna for this dish rather than used canned, but it works so well with canned tuna, I've never bothered.

Anchovies: the more expensive ones generally are better. They have smaller, less noticeable bones. If I'm serving it to folks who might be ambivalent or outright hostile to anchovies, I usually chop them up into pretty small pieces. They still give flavor to the salad, but they're more subtle that way. When I'm making it for just me and my wife, I still chop up most of the anchovies pretty small, but I like to keep a few larger pieces in for that occasional blast of anchovy.

Olives: here's a tip for pitting olives pretty easily: set the olives on a cutting board and gently smash them with the side of a large knife. Then pick the pits out.

Total prep time is 2.5-3.5 hours with cleanup, depending on how fast you are with your cutting and trimming.

Can be prepared a day in advance. If you do refrigerate it overnight, it'll taste best if you give it an hour or so out of the fridge to warm up.

Works well as an entree or a side dish. Always a big hit at potlucks. :D