Soak the dried mushrooms in 1 cup of boiling water for 20 minutes.
Melt the butter in a large frying pan and sauté the shallots for five minutes over medium heat, until soft and translucent. Add the garlic and thyme and cook for another 30 seconds.
Add sliced fresh mushrooms, season with salt and pepper and continue to cook over a medium heat until soft.
Drain the soaked dried mushrooms (reserving the soaking liquid) and add them to the pan.
Pour in the white wine, turn the heat to high and cook until the wine has evaporated.
Pour in the stock and reserved mushroom soaking liquid and cook again until the liquid has evaporated.
Turn the heat to medium, fish out thyme which will have given up their leaves, and add the cream, letting it bubble for a minute or two. Set the pan aside in a warm place.