1. Preheat the oven to 180C. Coat a small baking sheet with cooking spray, or use a non-stick baking sheet.
2. Mix together the salmon, onion, egg, breadcrumbs, mayonnaise, and dill. Make 4 patties (1/2 cup of salmon mixture each) about 10 cm in diameter.
3. Place the patties on the baking sheet and bake for about 20 to 22 minutes, until lightly browned.
4. Combine the yoghurt and mustard in a small bowl. Stir to mix thoroughly. Divide the yoghurt mixture evenly and spread it on the rolls. Serve the burgers on the rolls and top with the lettuce and tomato.
Calories 388, Kilojoules 1,624, Total Fat 15 g, Saturated Fat 3.5 g, Sodium 1,007 mg, Carbohydrate 32 g, Dietary Fibre 4.5 g, Protein 27 g