Bring a pot of water to a low boil over medium-high heat. Carefully add the eggs. Cook for 14 minutes. Transfer the eggs to an ice bath. Use a small metal spoon to crack the shell all over before peeling it off. Finely dice the eggs and set aside.
Prepare the salad:
Combine the diced eggs with the celery, red onion, parsley, and golden raisins in a large bowl. Add the drained tuna and flake it into pieces with a fork. Season with salt and pepper.
Make the dressing:
Combine the mayonnaise, vinegar, Dijon, and honey in a bowl and whisk until smooth. Taste and adjust the seasonings to your preference.
Finish the tuna salad:
Pour the dressing over the salad and stir gently to combine, breaking up the bigger pieces of tuna until the salad reaches your desired consistency. Add salt, pepper, and a pinch of sumac to taste.
Transfer the tuna salad to the refrigerator for at least 30 minutes.
To serve:
Serve the tuna salad on thick slices of toasted bread with tomatoes and baby greens. If you like, finish each toast with more black pepper and sumac. Enjoy!