Prep all the ingredients.
In a medium sized bowl, add the chopped celery, lettuce, sour cream and Dijon mustard. Add the lemon zest and juice from ½ a lemon and give all the ingredients a gentle stir.
Using a fork, flake pieces of salmon from the filet and add them to the rest of the salad. Again, give all the ingredients a gentle stir. You want to be careful so you end up with nice chunks of salmon.
Slice the avocado in half long ways, remove the pit and score the avocado halves into crosspatch cubes. Using a spoon, carefully remove the avocado cubes from each half being careful to preserve the skin.
Add the avocado cubes to the rest of the salad mixture and again carefully stir to combine all the ingredients.
Season with salt and pepper, taste and adjust seasonings.
Spoon the avocado and salmon salad back into the avocado skins and serve. The salad is delicious and the presentation is spectacular.