Cut the mushrooms in half or into quarters, depending on size. Cut the spring onions, including the green part, into rings. Set aside 2 tbsp of the greens. Remove the thyme leaves from the stalks, finely chop the sage.
Heat the clarified butter, fry the mushrooms in batches for approx. 4 mins. per batch, remove. Add a little clarified butter if necessary.
Add the onion and the pressed garlic, fry for approx. 1 min., return the mushrooms to the pan, stir in the herbs and mustard.
Pour in the cider, bring to the boil, simmer gently for approx. 10 mins. Stir in the sour single cream, season.
Chop the onion. Heat the butter and sauté the onion. Add the rice, sauté while stirring until translucent.
Pour in half of the apple cider and reduce completely. Add the remainder of the apple cider, reduce completely.
Grate in the apple. Salt the water and add gradually, stirring frequently, so that the rice is always just covered with liquid.
Allow the rice to simmer for approx. 25 mins. until it is creamy and al dente. Stir in the sour single cream.