Preheat the oven to 375 degrees. Grease a small baking sheet and set aside.
Put the tuna, celery and leaves, scallion, olives, chili pepper, and cilantro in a large bowl and season lightly with salt and pepper. In a small bowl, whisk the eggs, mayo, mustard, chile powder and a bit of salt and pepper together until combined. Pour the mixture over the tuna and fold with a rubber spatula until well combined, being careful not to break the tuna up too much. Sprinkle the flour over the mixture and fold until well combined.