The butter and cream cheese should be very soft, but not melted. I leave mine out on the counter, but if you're careful, you can use a microwave on a low setting.

Mix the ingredients for the tart dough in a large mixing bowl until a ball forms.

Refrigerate for an hour or longer.

Heat the deseeded grapes in a large dutch oven over medium heat. Remove any seeds as you come across them.

Stir in the sugar and a generous pinch of salt

Cook for 15 - 20 minutes until the liquid begins to thicken.

Make a slurry with the tapioca and some water and add it to the grapes.

The liquid will become cloudy, but will clear up as it cooks.

Continue to cook until the filling becomes quite thick.

Remove from heat and let cool. At this point, you could also store the grapes in the fridge for later.

Preheat the oven to 350°F

Roll out the dough into a large circle (or divide into smaller portions) and transfer to a baking sheet or pie pan.

Mound the cooked grapes in the center and pull the sides over the grapes.

Bake for 30 - 40 minutes or until the grapes are heated through and the crust is ready.