If using leftover, already cooked salmon, skip to step 5.
Add 1 tbsp of olive oil and a pinch of salt to salmon. Massage with hands to ensure even coating.
Add salmon to either a hot pan or a hot grill. Cook salmon all the way through and on both sides. The time will depend on how hot your bbq is and the thickness of your salmon. It took us about 8 minutes.
Allow salmon to rest for at least 5 minutes.
Heat a pan over medium-low heat.
Meanwhile, in a medium bowl, carefully remove salmon from skin and break apart into small pieces.
Add egg, egg yolk, breadcrumbs, green onions, mustard, Sambal and salt and pepper to bowl.
You should be able to make patties that stay together, so if they don't, add in 1/4 cup of breadcrumbs at a time until they do.
Add 1 tbsp of olive oil to hot pan and place burgers in pan. Cook until golden brown on both sides (about 3-4 minutes per side).
While burgers are cooking, add mayo, pickles, lemon juice to a small bowl. Add salt and pepper to taste. You can also toast the buns during this time.
On a toasted bun, put tartar sauce and place burger on top. Top with sliced red onions, sliced cucumbers and arugula. Enjoy!