Add the salmon to a bowl, and flake the meat with a fork. 

Place the onion, flour, cornmeal, egg, mayo and salt and pepper to taste into the bowl with the salmon, and mix well to combine. 

Form the mixture into patties about the size of a burger. 

Heat an inch or so of cooking oil over medium heat on the stove, and dry the salmon patties evenly on both sides until golden brown and cooked through.