Clean the leek and mushrooms and cut into slices. Dice shallot.
Fry the vegetables in the melted butter. Let it fry a little (vegetables should still have bite). Add the spaetzle. Warm up and mix well. Deglaze with apple spritzer. Season with salt, pepper, paprika powder and tomato paste. Stir well. Add cream. Mix in the mountain cheese at the very end. Season again to taste (enough salt?).
A mixed salad with radicchio and a sweet mustard vinaigrette is definitely enough!