Remove skin from salmon and discard. Flake the salmon with a fork; place in a medium mixing bowl.
Add a cup of mashed potatoes to salmon and mix lightly with a fork.
Add scallions, soy or Worcestershire sauce, lemon juice, lemon zest, dill, and parsley; toss lightly. Taste to see if any salt is needed. Add pepper.
Set out a plate or high-sided pan and add flour to it. Form fishcakes about the size of ping-pong balls between your hands and flatten them until they're about 1/2-inch thick. Dredge them in flour and set the floured fishcakes on a plate near stovetop.
When all the fishcakes have been formed, heat skillet on medium-high and then add sufficient extra-virgin olive oil to form a film about 1/8-inch deep. Allow oil to heat until it shimmers; lower heat to medium.
Put in fishcakes, but do not crowd them, or they will not become browned and crispy. Fry for 4 minutes; lift with spatula to see if they have become browned. When you're satisfied with their color, flip them over and fry the other side.
A little salad and a piece of your favorite fruit is all you need for a beautiful meal.