Peel and finely dice the onions. Clean the mushrooms, wash if necessary. Heat the fat in a large pan (or 2 pans). Fry the onions in it until translucent. Add the mushrooms and fry over high heat for about 10 minutes.
Add peas, season. Boil up with 3/8 litres of water, cream and possibly wine. Simmer for about 5 minutes. Cut gorgonzola into small pieces. Melt in the sauce while stirring. Thicken the sauce, season with salt and pepper.
Arrange everything with ham. It goes well with farmhouse bread.