I particularly love the balance in the salad - the acidity of the tomatoes and vinegar with the sweetness of the onions, the parsley which supplies a bitter, the salt, the olive oil, and the protein from the beans and eggs. It’s a complete, light meal in itself.
1/2 cup extra virgin olive oil
4 tablespoons white wine vinegar or sherry vinegar
3 cloves garlic, minced (about 1 tablespoon)
1 teaspoon Dijon mustard
1 teaspoon salt
1/2 teaspoon freshly ground black pepper
1/2 teaspoon Italian seasoning (or 1/2 teaspoon dry thyme or a teaspoon fresh chopped thyme)
You can chill the undressed salad up to six hours, until ready to serve. The Five Tastes - explanation in the Wikipedia