Combine the vinegar, jam and mustard in a small bowl and mix well. Whisk in oil, salt and pepper. Whisk until all the ingredients are well blended. Set aside.
Place the pine nuts in a small skillet and toast over medium heat for 4 - 6 minutes or until fragrant and golden brown. Remove pine nuts from the pan and cool completely. Wash the lettuce and berries. Thinly slice the cooked chicken and onion. Cut sugar snap peas in half. To serve, layer the lettuce, chicken, peas, blueberries and onion in a large serving bowl. Pour dressing over the salad just before serving. Toss gently to coat. Sprinkle with toasted pine nuts and serve. Delicious!
Can substitute sliced strawberries for blueberries.