What You'll Need
1 prepared tart dough
2 pounds of sliced nectarines
2 teaspoons of granulated sugar (may need less if the nectarines are sweet and ripe)
1 bunch fresh rosemary
Egg wash (1 egg whisked with 1 tablespoon whole milk)
Granulated sugar for dusting
Prep a large sheet pan (13-inch by 18-inch) with parchment paper and flour. Roll out your prepared dough in a large rectangle, place on to the prepared sheet pan, cover with plastic wrap and chill overnight.
The next day, preheat the oven to 375 degrees Fahrenheit. Place your prepared frozen galette dough on the counter. While it softens, add the sugar to a large bowl and gently rub 1 sprig of rosemary leaves into the sugar. Mix in your nectarines until fully coated in the sugar.
Prep your egg wash.
Gently place the nectarines in the middle of the galette dough leaving about 2 inches of dough. Fold the edges over the nectarines (it's okay if it's not perfect). Brush the edges of the tart with the egg wash and sprinkle sugar over the entire galette. Put remaining rosemary in the middle of the galette. Put the galette in the oven and reduce the heat to 350 degrees Fahrenheit. Bake for 30-45 minutes until golden. If the edges are burning you can wrap them in tin foil.
Enjoy warm with ice cream or whipped cream. Keep it in the fridge for up to one week.