Add the avocado to a bowl and top with lemon juice, salt, pepper, and garlic powder. Mash the avocado with a fork until it's a puree with no large chunks.
Combine the tuna, celery, apple, and red onion in a bowl. Add the avocado mash and stir to coat the tuna salad.
Serve topped with green onion and additional salt and pepper to taste!
Notes
Dice everything around the same size. You want a fine dice on all of your fruits and veggies so you don't have any giant pieces that feel out of place.Grab a guacamole cup for a big shortcut. I use the Good Foods avocado mash for the ultimate hack. These are sealed, so you don't have to worry about browning or picking the perfect avocado. How to prep ahead for lunch.
Prep the components ahead of time and store them separately. This will keep everything fresh and crisp! I dump it all into a larger container and just mix with a fork.
Add extra lemon juice to prevent the avocado from browning.