Pulse flour, salt, and butter in a food processor till butter is pea sized. Add egg and pulse till dough begins to form.
Knead dough together until it becomes one piece. Wrap in plastic wrap and let rest for at least an hour.
Preheat oven to 375°F
Mix remaining ingredients (blueberries through almonds) together in a large bowl.
Roll dough into a circle (or two) that is about ¼” thick. Scoop filling into center of dough, leaving a 1.5” border around the rim. Fold dough over filling, overlapping it as you go around the circle and pinching it tight so it doesn’t unfold while baking.
Bake on sheet pan for about 45 minutes or until crust is golden brown and cooked all the way through.