Cut the salmon into cubes and place in a food processor. Process until it is coarsely ground. You want it to be the texture of ground beef - don’t take it too far. 

Transfer the salmon to a large bowl. To the bowl, add the bell pepper, garlic, 3/4 of the ginger, soy sauce, green onions, sesame oil, grill seasoning, and pepper. Stir until combined.

Form the mixture into 4 equal sized patties that are about 1 to 1 1/2 inches thick. Drizzle with the oil.

Heat a large nonstick skillet or griddle over medium-high heat. Add the patties and cook until golden brown, about 5-6 minutes, then carefully flip and cook the second side, another 5 minutes.

While the patties are cooking, combine the mayonnaise, wasabi paste, lime juice, and remaining ginger.

To serve, spread the ginger-wasabi mayonnaise on the buns and top with a salmon burger, lettuce,  and sliced onion.