Remove bones and skin from salmon. Breaking into chunks, place in a food processor. Pulse until salmon is cut into very small chunks. Don't pulverize.
Mix all ingredients together and form into patties. Turning only once, grill over medium heat until meat thermometer reaches 150 degrees. In the meantime, grill sliced onion alongside until soft and just turning brown. Butter a hamburger bun and toast on grill. Assemble and enjoy.