In a large bowl, mix together the whole-wheat bread crumbs, mayonnaise, beaten egg, chopped chives, parsley, and lemon zest. Season with ½ of the kosher salt and the black pepper, stirring until well combined. Gently fold in the flaked salmon and diced bell pepper, ensuring an even distribution of ingredients. Shape the mixture into 8 equal patties.

Warm 1 tablespoon of olive oil in a large skillet over medium-high heat. Place half of the salmon patties in the skillet and cook until the bottoms turn golden brown, about 4 to 5 minutes. If they start browning too quickly, reduce the heat slightly. Flip each patty and continue cooking for another 4 to 5 minutes, or until the other side is golden. Transfer the cooked patties to a plate and repeat the process with the remaining olive oil and salmon cakes.

In a separate small bowl, whisk together the Greek yogurt, freshly squeezed lemon juice, and the remaining ¼ teaspoon of kosher salt until the mixture is smooth and creamy. Serve the salmon cakes warm with a dollop of the lemon yogurt sauce on top or on the side.