Chop peeled onion, garlic, passed through a press. Saute onion and garlic in 2 tablespoons of butter in deep pan. Grate nutmeg , add salt and pepper. Slice mushrooms, sprinkle with lemon juice, add in the pot and fry until golden. Pour in white dry wine, sprinkle with crumbled broth cube, add chopped parsley. Melt 1 tablespoon of butter in a saute pan, add flour and roast it until cream colour. Pour the cream in a thin stream, stirring occasionally, cok on low heat until thickening. Add mushrooms with onion in the sauce and simmer on low heat for another 10 minutes.