Start boiling the water for the gnocchi. Add salt once it starts to boil.
Wash and slice the radicchio. Melt a little butter in a frying pan or skillet. Add the sliced radicchio and cook until it has reduced in volume by at least half and darkened in colour. (You can also do this with a little water or oil instead of butter)
Sprinkle 1-2 tablespoons of Balsamic vinegar onto the radicchio. Turn up the heat and cook until caramelized. You will need to keep stirring it so it doesn’t burn. If you think it’s too sour add a teaspoon of sugar. The older the Balsamic the sweeter it will be.
Put the milk in a frying pan or skillet and start to heat it.
Add a piece of gorgonzola and stir till it melts, (if you want a denser sauce you can add a little butter). Continue to add pieces of Gorgonzola and if the sauce is too thick a bit more milk a little at a time.
It is important not to overcook the gorgonzola. For a delicate taste it must dissolve at a medium temperature. Turn off the heat and add some grated Parmigiano and pepper if desired.
Cook the gnocchi in the boiling salted water. As they start to rise to the surface of the water scope them out with a slotted spoon and add them to the gorgonzola sauce. If the sauce is too thick you can also add some gnocchi cooking water to make it more liquidy.
Mix the sauce and the gnocchi together and serve immediately on a bed of the caramelized radicchio. Sprinkle with chopped walnuts and grated Parmigiano if desired.