Mushroom sauce and Kale Knödel

Name: Mushroom sauce and Kale Knödel
Cuisine: European, German
Ingredients: 1 kg (about 8 medium sized) of “starchy” potato (ex; russet) or if you use a less starchy kind of potato (yukon,kennebec), double the amount of both semolina and starch to the mix; 80 ml of milk; 2 tbsp of starch (cornstarch); 2 tbsp of semolina; 1 tbsp of butter; 1 hand of finely chopped kale or spinach; 1 slice of white bread toasted cut into small cubes optional; salt, pepper; 1 onion finely chopped; 200ml of cream; 200g of button mushrooms sliced; 100ml of vegetable broth (or chicken, beef); 50ml of white wine; 1 tbsp cornstarch (mix it with the cold white wine, so it dissolve better); fresh flat-leaf parsley finely chopped; nutmeg; salt, pepper