Preheat the oven to 180°C (356°F) and line a baking tray with parchment paper.
In a large mixing bowl combine 2 cups cooked quinoa, 1 cup flaked steamed salmon, lemon zest (from ½ lemon), 1 tablespoon lemon juice, 2 lightly beaten egg whites, and 1 tablespoon chopped fresh dill; season with salt and pepper and mix until well combined.
Shape the mixture into burger-style patties and place them on the prepared tray.
Chill the patties in the freezer for 10 minutes (or refrigerate for a couple of hours or overnight) to firm up.
Place 3 tablespoons flour on one shallow plate and 3 tablespoons breadcrumbs on another. Lightly dust each patty with flour, brush with the beaten egg white, then coat evenly with breadcrumbs.
Heat a cast iron skillet or frying pan over medium heat and add a drizzle of extra virgin olive oil. Sear the fishcakes 2 minutes per side until golden.
Transfer the seared fishcakes to the oven and bake for 10 minutes, or until crispy, golden and cooked through.
While the fishcakes cook, make the yogurt dip by stirring together 1 cup low-fat Greek yogurt, zest of ½ lemon, 1 tablespoon chopped fresh dill, and salt and pepper to taste; chill until serving.
Serve the fishcakes piping hot with the dill-yogurt dip.