It doesn't get easier or more elegant than this. And frankly its borderline sacrilegious to not be using mouthwatering heirloom tomatoes right now at their peak-of-ripeness with the freshest olive oil in the world. Simply unthinkable.
6 cups baby arugula washed, spun dry
2 cups of sliced heirloom tomatoes
1/3 cup freshly torn basil leaves
1/2 small red onion, very thinly sliced
1/2 pound mozzarella fresca thinly sliced or bocconcini sliced in half
1/2 cup extra virgin olive oil
2 tablespoons Champagne Vinegar
2 tablespoons apricot white balsamic - or white balsamic of your choice
1 teaspoon grainy mustard
1/2 teaspoon salt
freshly ground pepper to taste
Combine the Champagne and white balsamic in a small bowl and place the red onions in the bowl to quickly "pickle" for 5 minutes or up to 10 minutes. The vinegar will turn a light shade of pink. Remove the onions and reserve. Whisk the mustard and salt into the vinegar. Slowly drizzle in the olive oil, whisking briskly and constantly to create a semi-emulsion.
Just before serving dress the baby arugula with just a few drizzles of the vinaigrette. Arrange the dressed arugula in layer in a shallow, wide bowl or platter. Add the pickled onions, sliced tomatoes, cheese and torn basil leaves over the top. Add a few more drizzles of the vinaigrette and fresh cracked pepper to taste. Serve immediately with crusty bread to mop up any dressing left on the platter/bowls.