Preheat oven to 180°C.
Put the potatoes and kumara in a saucepan and cover with water. Bring to the boil and boil for 2 minutes, then drain and cool slightly. Grate into a bowl and toss with the olive oil and salt and pepper to taste.
In a saucepan, melt butter over a medium heat, then add the leek and cook for 5 minutes. Blend in flour and cook for 3 minutes, stirring constantly.
Slowly add in milk and whisk until the sauce thickens. Season to taste.
Stir in Sealord Smoked Flavour Fish Fillets and peas and place mixture in an ovenproof dish. Top with potato and kumara. Bake for 30-35 minutes.
While pie is cooking, prepare and cook broccolini or other green veggies.