Place salmon, cilantro, hoisin sauce and mayonnaise in a food processor. Blend until coarsely ground. Transfer mixture to a medium bowl.
Mix in green onions, ginger, garlic, jalapenos, sesame oil, salt and pepper. Form into patties. Cover, refrigerate at least 1 hour or up to 4 hours.
When salmon patties are ready, preheat grill to medium high. Lightly brush buns with butter and grill until grill marks appear and buns are toasty. Remove buns and grease grill grate with vegetable oil.
Grill salmon burgers until fish is cooked through, about 2 minutes per side. Transfer burgers to buns and top with lettuce, tomato and onion.