For the salad: Pack all the ingredients for the salad in individual bags and place on a sheet pan.
For the Thousand Island dressing: Combine all the dressing ingredients in a bowl and mix. Pour into a quart container and put the lid on.
To assemble: Arrange the lettuce on the bottom of a platter and sprinkle ham, eggs, cucumber, tomatoes, avocado, Cheddar, onions, edamame, and parsley on top. Drizzle some dressing over the salad. Garnish with scallions. Serve extra dressing on the side.