Grate the potatoes rinse in water and drain the excess water.
Transfer it to another bowl.
To the potatoes, add salt to taste, cracked black pepper to taste, corn flour, finely chopped parsley and mix them all.
In a pan, melt butter and add the rosti mix.
Cook on both sides for two minutes till it turns brown in colour.
For the mushroom sauce, take butter in a pan and add finely chopped onion, sliced mushrooms, lemon juice, salt to taste, cracked black pepper to taste, fresh cream and chopped chives mix well and cook.
Cut the prepared rostis into triangular shapes and serve them with mushroom sauce.