In a large bowl mix together the flour, salt, and sugar.
Grate frozen butter into flour mixture and blend with pastry blender or two forks until the mixture resembles coarse meal.
Add water 1 Tbsp. at a time while mixing with a spoon, until dough comes together.
Place dough onto a well floured board and roll into a circle, rolling from center to edge.
Dough should be about 1/4 inch thick.
Preheat oven to 375 degrees.
In a medium bowl, toss grapes with olive oil, thyme, and oregano.
Place grapes on baking sheet and bake for 15 minutes, until grapes begin to wrinkle.
Turn oven up to 400 degrees.
Place tart crust onto a large baking sheet.
Combine cream cheese and goat cheese.
Spread cheese mixture onto crust, leaving a 1 1/2 inch border.
Spoon the grapes on top of the cheese mixture.
Fold the edge of the crust over the edge of the filling.
Brush the folded edge with the beaten egg.
Bake for 20-30 minutes, until crust is golden brown.
When tart comes out of oven, drizzle with balsamic vinegar as desired.