For burger: In a food processor, puree 1/2 cup of the salmon scraps with dijon mustard and Frank's RedHot.
Add remaining salmon and shallots. Plus until roughly chopped. Transfer to a medium stainless steel bowl and mix bread crumbs and lemon pepper in by hand. Divide mixture into 4 equal parts and form into patties. Cover and refrigerate for at least 30 minutes.
Preheat grill to high, ensure well oiled. Grill patties on both sides until desired doneness.
For burger build: Toast burger buns. Spread both the base and crown of the buns with 1 tablespoon of lemon pepper aioli. Place 1/4 cup of arugula on base on bun. Top with grilled salmon burger. Finish with sliced of red onion and sprouts. Serve warm with desired sides.