Peel the 800 g of Agria potatoes.

Coarsely grate the peeled potatoes into a mixing bowl.

Wrap the grated potatoes in a clean kitchen towel. Squeeze firmly to remove as much liquid as possible.

Season the squeezed potatoes with 1 g salt and 0.25 g ground nutmeg. Add 1 g rosemary and mix thoroughly.

Heat 15 ml neutral vegetable oil in a 26 cm frying pan over medium-high heat. Add the seasoned potatoes to the hot oil.

Spread the potatoes into an even 26 cm galette. Press down firmly with the spatula.

Reduce to medium heat and cook the rosti for 5 minutes. Cook until the underside is golden brown.

Place a large plate over the frying pan. Carefully invert the pan to turn the rosti onto the plate.

Slide the rosti back into the frying pan with the uncooked side down. Cook over medium heat for 10 minutes until crisp and cooked through.

Transfer the cooked rosti to a serving plate. Spoon 15 ml crème fraîche over the top.

Finely chop a little rosemary and scatter it over the rosti. Finish with 1 g lemon zest, 0.25 g black pepper, and extra salt to taste.

For make-ahead serving, preheat the oven to 200°C. Reheat the rosti for 5 to 10 minutes until hot and crisp.