Place chicken on the rack of an uncovered grill directly over medium coals. Grill for 12 to 15 minutes or until chicken is no longer pink (170 degree F), turning once. Cool slightly; cut chicken into pieces, about 2x1-inches in size.
Meanwhile, in a large bowl combine spinach, arugula, onion, and basil. To serve, divide the spinach mixture among dinner plates. Arrange the plums, strawberries, and chicken on top of spinach mixture. Drizzle with the Strawberry Dressing. Makes 4 servings.
In a food processor bowl or blender container combine strawberries, strawberry topping, olive oil, vinegar, ginger, salt, and black pepper. Cover and process or blend until smooth. Makes about 3/4 cup.