How to Make It
To prepare vinaigrette, combine first 7 ingredients in a small bowl; stir well with a whisk.
To prepare salad, place the greens on a platter. Sprinkle half of onion and half of basil evenly over greens. Arrange tomato slice halves over basil. Top with the remaining onion and basil. Drizzle evenly with the vinaigrette.