1kg / 2.2lbs of potatoes, boiled in their jackets the day before
2 to 3 tablespoons of butter
1 to 2 medium onions
salt to taste
In this recipe you can choose to either make one large roesti or 4 individual ones. Firstly peel the cooked potatoes and grate them through a coarse grater. Slice the onions into thin wedges (Lyonnaise). Melt the butter (please resist the temptationto use oil as you will not have the same result!) in a non-stick frying pan and add the onions and sweat them until they look glassy and transparent. Add the grated potatoes and the salt and stir through. Fry while stirring them around in the pan for about 3 to 5 minutes. Press together to form a flat cake and fry over medium heat until there is a golden crust on the bottom. Place a serving platter on the pan and turn the pan upside down, so the Roesti falls on the platter with the crust on top. Alternatively, toss the roesti into the air and flip it like a pancake back into the pan, then slide it onto the serving platter and serve immediately.