Bring chicken stock to a boil in a large saucepan; reduce to a simmer and keep warm while preparing risotto.
Heat olive oil in a 4-quart saucepan. Add onion and a pinch of salt and saute over medium-low heat until it is soft and translucent but not at all browned. Add rice and continue to saute, coating rice with the oil, until grains are lightly toasted, about 4 to 6 minutes. Adjust heat as necessary to keep pan temperature relatively constant. Add white wine and stir until it is almost completely absorbed.
Begin adding simmering stock to rice, 1 ladleful at a time, stirring the rice constantly and continuing to cook at a constant low simmer. Add more stock each time the last addition is nearly, but not completely, absorbed.
About 15 minutes after you begin adding stock, test rice by biting into a grain. It is done when it is almost cooked but still al dente, you should be able to feel a little bite in the middle of the grain, but it should not taste uncooked or gritty. Don't worry if you have not used all the stock.
Remove risotto from heat and stir in butter, Parmesan and 1 cup of Cabernet wine until butter and cheese are melted. Adjust seasoning as necessary with salt and pepper. Transfer to a platter or individual shallow bowls. Garnish with a drizzle of the wine and some grated Parmesan. Serve immediately.
Recipe courtesy of Michael Chiarello