Drain canned tuna very thoroughly, blot lightly and flake while leaving some texture.
Whisk egg, mayonnaise, Dijon, green onion, parsley, lemon zest, garlic, salt and pepper.
Fold in tuna and panko until a squeezed spoonful holds without dripping or crumbling.
If wet add 1 tablespoon panko; if dry add 1 teaspoon mayonnaise.
Form four 3-inch patties, compress the rims and refrigerate 15 minutes.
Preheat to 380°F if recommended, oil the basket and mist both sides of the patties.
Cook 5 minutes, turn with a wide spatula and cook 3 to 5 minutes longer until golden and 160°F.
Rest on an open plate for 3 minutes before serving.
