Step 1

Preheat oven to 180°C. Cook the pasta in a large saucepan of salted boiling water following packet directions or until al dente. Drain and return to the pan.

Step 2

Meanwhile, heat half the oil in a large saucepan over medium-high heat. Add the leek and cook, stirring, for 4-5 minutes or until soft. Transfer to a heatproof bowl.

Step 3

Melt the butter in the pan over medium heat until foaming. Add the flour and cook, stirring, for 30 seconds or until the mixture bubbles. Remove from heat. Gradually add the milk, stirring constantly, until smooth. Place over medium heat and cook, stirring constantly, for 5 minutes or until the mixture boils and thickens. Remove from heat.

Step 4

Add the cheddar, lemon rind and mustard to the milk mixture and stir until the cheddar melts. Season with salt and pepper. Add the cheddar mixture, leek and dill to the pasta and stir until well combined. Gently stir in the salmon.

Step 5

Spoon the pasta mixture into a 2.5L (10-cup) capacity ovenproof dish. Combine the breadcrumbs, parsley and remaining oil in a small bowl. Sprinkle over the pasta mixture. Bake for 35-40 minutes or until the top is golden. Serve with mixed salad leaves.