Method

• 1.
  Place potatoes in a pan of cold, salted water and bring to the boil. Reduce heat to low and simmer 8 minutes. Drain and cool slightly. Peel potatoes, then coarsely grate into a bowl. Stir in horseradish and season well.
• 2.
  Form into 4 patties, ensuring they have ragged edges and squeeze out any moisture. Dust lightly with flour, then cover.
• 3.
  Break eggs into a frypan of boiling water. Reduce heat to low, cover and simmer for 1 minute.
• 4.
  Uncover, turn heat off and allow eggs to sit for 10 minutes. Meanwhile, heat butter and oil in a non-stick frypan over medium heat. Add rosti and cook for 2 minutes each side or until golden.

• 5.
  Place each rosti on a warm serving plate, top with a folded slice of salmon. Use a slotted spoon to remove eggs, cut off rough edges, then place on top of salmon. Drizzle with hollandaise, garnish with chives, season and serve with rocket.
• 6.
  Hollandaise: Place 2 egg yolks in a food processor and season. Heat 1 tablespoon each of white wine vinegar, white wine and lemon juice in a pan over medium heat. Simmer for 1 minute, then add to egg with the processor motor running. Slowly add 110g of melted, unsalted butter, processing until a smooth sauce. You can make this in advance and keep it warm in a thermos.