For salad, combine smoked chicken or turkey, celery, and green onion in a small mixing bowl. Stir in mayonnaise or salad dressing, lemon peel, lemon juice, and pepper. Cover and chill up to 4 hours. Cut tomatoes in half lengthwise. Scoop out and discard the tomato pulp, leaving 1/4-inch-thick shells. Place tomato shells, cut sides down, on paper towels to drain. Let stand for 30 minutes.
Just before serving, stir watercress, arugula, or spinach and almonds into the chicken mixture. Spoon some salad into each tomato shell. Arrange on a platter. Serve immediately or cover with plastic wrap and chill in the refrigerator up to 1 hour. Makes 20 to 24.