Oven cooked button mushrooms with Vacherin on top

Serves 4:

11 to 16 big button mushrooms
150 g of Vacherin
30 g of butter
2 slices of prosciutto ham
Ground pepper

Rinse the mushrooms in a mixture of water and vinegar; cut the stems and chop finely.
Melt the butter in a saucepan and sweat the caps for 3 to 4 minutes.
Set the caps aside. In the same butter, quickly fry the chopped mushroom stems; add salt, pepper and nutmeg.
Add the finely chopped cooked ham and melt the Vacherin on top.
Place everything in an earthenware or heat-resistant dish. Place in the oven preheated at 220° C and brown for 3 to 4 minutes.