The tart can be refrigerated for up to 4 days.
To toast and skin hazelnuts, preheat the oven to 350 degrees. Spread the hazelnuts in a pie plate and toast for about 12 minutes, until golden and the skins blister. Let cool slightly, then transfer the hazelnuts to a kitchen towel and rub off the skins. Let cool.
Pair it with a sweet, dried-fruit-scented Banyuls.