Add the wine and cook briefly to evaporate some of the alcohol.
The pot will boil violently, and the wine will almost completely evaporate.
Stir in the wine and cook quickly until wine evaporates.
Add the wine and cook, stirring, until the wine has evaporated, about 3 minutes.
Add the hazelnuts and continue to cook until the wine has evaporated.
Pour in the remaining wine and cook until the wine has evaporated.
Add the remaining wine, and cook over high heat until nearly all the wine evaporates.
Cook a few minutes longer, until wine has mostly evaporated.
Add the wine, bring to a simmer, and cook until the wine has evaporated.
Bring to a simmer, and cook until almost all the wine has evaporated, about 30 minutes.