Drain and flake salmon. Combine lemon juice and mustard. Blend flaked salmon with breadcrumbs, green onions, and lemon juice-mustard mixture. Mix in egg whites until well blended. Form mixture into 4 patties and cook on a lightly oiled grill or sauté in skillet until golden brown on both sides. Serve each burger on a bun with lettuce, tomato slices, and condiments as desired. Makes 4 servings. Special thanks to Alaska Seafood