With a small pair of tweezers, run your hands over the smoked rainbow trout fillets and remove any bones you feel or see. Small bones are okay, so don't stress if you can't get every last one. Flake the rainbow trout into a small bowl and set aside.

Place the diced potatoes in a large, heavy pot and add water so that the water covers the potatoes with about 1 inch of space. Bring the potatoes to a boil, then reduce heat and cook just until fork tender, about 12 minutes. Drain and transfer to a large bowl to cool for ten minutes.

Mash the potatoes with a heavy spoon until smooth but still slightly lumpy. Add the trout, green onions, parsley, 1 egg, the salt, pepper and cayenne and mix until smooth.

In a durable, medium-sized saucepan (i.e., cast iron) pot or deep fryer, heat enough oil to come halfway up the sides over medium heat until the temperature of the oil reaches 350 degrees Fahrenheit.

Prepare three small bowls in a line. Pour the flour into one. In the second, beat together the remaining egg and milk. Pour the breadcrumbs in the third bowl.

Form the trout mixture into balls about 1 1/4-inches in diameter and 1 heaping tablespoon each. You should have about 24 balls total.

One at a time, dip the trout balls in the flour and roll to coat evenly on all sides. Shake to remove any excess flour, dip in the egg wash, and then roll in the breadcrumbs. Place on a baking sheet lined with plastic wrap.

In batches, gently add the balls to the oil and cook until golden brown on all sides, about 2 1/2 minutes. Remove with a slotted spoon and drain on paper towels.

Serve immediately.