That's a meal in itself and doesn't need anything else substantial with it! Especially if it's going to be hot out (it is here) I'd maybe have some cottage cheese and sweet fruit along with it, and fizzy mineral water.

All it needs is a loaf of good bread.

I'd say, serve some nice bread on the side, and maybe some grilled shrimp, a bowl of olives, a couple of nice cheeses and a fruit platter.

Now I am really craving this salad. Hope you have a great dinner!

I would grill wide slices of red and yellow peppers and zucchini (cut the ends off, cut in half then slice lengthways so you have strips of zucchini about 3" x ½". Brush a ridged griddle (or ridged pan) with olive oil, and grill the peppers and zucchini on both sides until the peppers have charred bits on them, and the zucchini are soft. Takes about ten minutes on a hot griddle. Spray or brush with more oil, as needed.

This dish can be eaten warm or lukewarm alongside the salad.

Going along with what Kangaroo said, and the Italian idea, maybe some sort of organized-ish antipasto platter? Prosciutto, melon, olives, roasted garlic if you're in the mood, artichoke hearts, sun-dried tomatoes, etc.?

I'm thinking dessert. And bread. And that's it. Dessert. Bread.

I like occiblu / Kangaroo's idea. No matter how tasty and substantial the salad is, some people just feel it isn't quite a meal.

Oh, WINE to go with the good loaf of bread everyone has suggested.