Place potato in a large saucepan and cover with cold water. Bring to the boil over high heat. Cook for 15 mins or until potato is tender. Drain. Return to the pan with the buttermilk. Use a potato masher or fork to mash until smooth.
Meanwhile, heat butter in a frying pan over low heat. Cook the leek, stirring, for 5 mins or until soft.
Spoon the leek over the mashed potato and fold to combine. Cover to keep warm.
Cook the sausages in the frying pan over medium heat, turning occasionally, for 8 mins or until cooked through. Transfer to a plate. Cover to keep warm.
Stir the gravy powder and 1 cup (250ml) boiling water in a large jug until combined. Divide the mash and sausages among serving plates. Drizzle with gravy. Sprinkle with parsley.
Serving size: 4
Recipe courtesy of taste.com.au