1

Preheat the oven to 190°C, fan 170°C, gas mark 5. Mist a baking sheet with the spray.

2

Put the potatoes in a pan of cold water and bring to the boil. Simmer for 5 minutes, or until softened slightly, but still a bit firm in the middle. Drain.

3

When cool enough to handle, grate the potatoes into a bowl and add the onion with a pinch of salt. Stir well to combine.

4

Shape into 3 equal balls, transfer to the baking sheet and flatten with your hand. Mist with cooking spray and bake for 30 minutes, turning once after 20 minutes, until crisp and golden.

5

Put the rösti on a plate and top with the yogurt and salmon. Serve with freshly ground black pepper.