Preheat oven to 375 degrees. Roll out ½ recipe of galette dough as described in dough recipe. Wash and dry peaches or nectarines. Cut in half and remove pits. Cut halves into ¼-inch slices. Place cherries and peaches/nectarines in a mixing bowl. In another bowl, combine sugar, cinnamon, nutmeg and cornstarch. Toss dry mixture into the fruit mixture. Place fruit filling on prepared galette dough round, leaving a 1-inch border. Fold dough border over fruit. Pinch dough border to create pleats.

In a small mixing bowl, whisk together egg and cream. Brush pleated dough side with egg wash. Sprinkle 1 tablespoon raw sugar over galette. Bake in preheated oven until fruit filling is bubbly and crust is light brown; about 40 minutes.

While galette is baking, place apple jelly in small saucepan. A few minutes before galette is done, heat jelly on low heat to melt. Remove galette from oven. Brush melted apple jelly on top of fruit. Sprinkle with remaining 1 tablespoon raw sugar. Cool galette for 20 minutes before serving.