How to Make It
Thinly slice avocado and arrange slices along one side of a wide, shallow bowl; brush lightly with vinegar. Mound lettuce in center of bowl, and arrange tomatoes opposite the avocado.
In a small bowl, mix 3 tablespoons vinegar, olive oil, and 1/2 teaspoon salt.
Pour dressing over salad; mix gently at the table, adding pepper and more salt to taste.