In a saucepan, toast the rice with butter and onion; deglaze with white wine.
When the wine has been absorbed pour in 1 or 2 ladles of boiling broth until the rice is covered, adjust the heat to a very calm simmer and begin to cook ("pull") the risotto, turning almost continuously with a wooden spoon. Only when the broth has been fully absorbed do you pour in another ladleful. Continue in this way, with additions of one ladle at a time and only when the one poured previously has been completely absorbed.
A few minutes before the rice is cooked (approx. 20 min), add the broken Gorgonzola, cream and chopped walnuts, mixing the ingredients together.
When cooked, turn off the heat and stir in butter, grated cheese and parsley.
Cover and let stand 2 minutes before serving.