In a medium bowl, combine tuna, Greek yogurt, celery, onion, Dijon, relish, lemon juice and garlic powder; season with salt and pepper, to taste.
Place eggs in a large saucepan and cover with cold water by 1 inch. Bring to a boil and cook for 1 minute. Cover eggs with a tight-fitting lid and remove from heat; set aside for 8-10 minutes. Drain well and let cool before peeling and halving.
Place lettuce leaves into meal prep containers. Top with tuna mixture, eggs, almonds, cucumber and apple.