Clean and trim the mushrooms and, depending on their size, cut them into smaller pieces. Clean, wash and cut spring onions into rings. Dice ham. Shrimps wash, dab dry and cut coarsely. Peel and wash potatoes. Peel onions. Roughly grate potatoes and onions. Stir in egg, shrimps and flour. Season with salt, pepper and nutmeg
Heat 2 tablespoons of oil in portions in a coated frying pan (approx. 26 cm Ø). Put about half of the dough into the pan and fry over medium heat for 6-7 minutes until brown. Turn with a flat lid and fry for another 6-7 minutes until crispy. Keep the finished Rösti warm in the oven. Fry the rest of the Rösti dough in the same way
In the meantime, heat 2 tablespoons of oil in another pan. Fry the mushrooms and ham for 4-5 minutes while turning, add the spring onions and continue to fry for 2-3 minutes. Season the mushroom mixture with salt and pepper, stir in crème fraîche, but do not cook any more. Season to taste again. Serve Rösti with fried mushrooms