Soak dried mushrooms in 150ml boiling water for 30 minutes, then strain and squeeze dry.
Reserve 4 mushroom pieces and process the rest with shallots, flat mushrooms, nutmeg, and seasoning.
Sauté the chopped mixture in butter for 25-30 minutes until the liquid evaporates.
Preheat the oven to 180°C and boil a kettle for the water bath.
Stir 1 tablespoon of crème fraîche into the mushroom mixture and divide among buttered ramekins.
Crack one egg into each ramekin, season, and top with the remaining crème fraîche.
Place a reserved mushroom on top and put ramekins into a baking tin.
Fill the tin with boiling water halfway up the ramekins and bake at 180°C for 15-18 minutes.