Preheat oven to 300 F. In a bowl lightly whisk egg. Add sugar and salt. Mix in the walnuts and pour onto a lined baking sheet. Spread out into a single layer. Baked for 15-17 minutes tossing halfway. Remove from oven and cool.
Dressing
In a small bowl, whisk together the ingredients. Refrigerate until ready to use.
Salad
In a large bowl add celery, grapes, apple, lettuce and parsley. Pour in dressing and toss to combine.
Arrange Boston lettuce leaves on a serving platter. Carefully scoop on the salad. Sprinkle on cheese, walnuts and pomegranate seeds. Serve immediately.