Using a fork, poke holes around all sides of the russet potatoes. Place potatoes on a microwave safe plate then cook in the microwave on heat for about 15 minutes or until soft and cooked through.
Allow potatoes to cool slightly, then scoop out their flesh into a large mixing bowl. To the bowl, add the thawed spinach, smoked salmon, egg, breadcrumbs, greek yogurt, green onions, and a healthy pinch of salt and pepper. Stir the mixture until everything is evenly incorporated. Form mixture into 8 even size patties.
Coat a large nonstick skillet with cooking spray then heat it over medium-low heat. Once the pan is hot, add the patties then cook on each side for about 4-6 minutes or until golden and crispy. You’ll likely need to do this in two batches.
Place cooked burgers on the bottom half of the brioche bun then top with arugula, mayo, and mustard then the top half of the bun end enjoy!