Preheat the oven to 425.
In a food processor, chop the almonds until finely ground. Add the sugar and salt, if using.
With the food processor running, add the butter and egg and mix until a smooth paste forms. Set aside.
Working with one sheet of puff pastry on a lightly floured surface, (wrap the second and freeze, or double this recipe to make 2 galettes), roll out until it's about an inch or so larger than its original size.
Trim the corners off to make a more oval shape.
Turn and fold the edges in about one inch to make a rim around the pastry.
Poke holes in the bottom of the crust with a fork.
Transfer to a foil or parchment-lined baking sheet and brush the entire surface and crimped edges with the beaten egg and milk mixture. Chill in the freezer 5 minutes.
Remove from the freezer and spread the bottom of the pastry with an even layer of the almond paste. Chill 5 more minutes.
Remove from the freezer and add the cherries to the top of the almond paste.
Bake 10 minutes, then remove from the oven and sprinkle with one tablespoon granulated sugar.
Return to the oven and bake until deeply golden brown, about 15 minutes more.