Fish pie with potato topping

1 Preheat oven to 180°C. Add potato to a large saucepan of water. Set a steamer over pan. Bring potato to the boil. Place cauliflower in steamer, cover and steam for 15 minutes to cook both veges. Drain potatoes.

2 Meanwhile heat olive oil in a flameproof baking dish set over medium heat on the stovetop. Add flour and stir continuously for 2 minutes. Whisk milk and fish stock into flour, a little at a time, to make a smooth sauce. Add mustard and lemon juice, whisking. Add all seafood with broccolini and corn; stir well and season with pepper. Switch off heat and set baking dish aside.

3 Blitz steamed cauliflower in a food processor or blender until smooth. Add cooked potato and pulse (or blend) on low speed until veges are well combined. Spoon cauliflower-potato mixture onto fish filling in reserved baking dish; spray with olive oil.

4 Transfer dish to oven and bake for 40 minutes or until golden. Remove pie from oven, leave to cool for 5 minutes and serve.