Heat the stock in a saucepan and keep warm over low heat.
Heat 2 tablespoons oil in a large saucepan and cook the shallot over low heat until softened.
Add the rice and cook for a few minutes, until the rice becomes translucent and has absorbed the oil. Turn up the heat, pour in the wine and simmer until the alcohol has evaporated and the wine is mostly absorbed by the rice.
Reduce heat to medium and begin to add the hot stock, a ladleful at a time, stirring after each addition and adding the next only when the first one is fully absorbed. The rice will take about 18 to 20 to cook fully.
In a small saucepan cook the pancetta until browned and crisp.
Once risotto is cooked, remove pan from heat and stir in butter, Gorgonzola and half of the pancetta. Fold in well, until the cheese melts. Then add grapes and gently stir.
Divide between serving plates and sprinkle over the remaining pancetta. Dust with some freshly ground black pepper and serve.
If you prefer a more delicate flavour, replace Gorgonzola with Taleggio, another Italian soft but less sharp cheese.
If you use a vegetable stock made from stock cubes or bouillon powder, that along with the salty pancetta and cheese means that you shouldn't need to add additional salt to the dish. However, if you use a salt-free stock, you may want to add salt to taste towards the end of cooking.