• Preheat oven to 375 F. Combine water and vinegar in a small bowl. 
• Combine flour and salt in another bowl. Using a pastry cutter or your fingers, cut butter and cream cheese into flour mixture until mixture resembles coarse crumbs with some larger pieces remaining.
• Add water mixture to dough in a slow, steady stream, stirring, until mixture just begins to hold together. (Alternatively, pulse ingredients in a food processor.) 
•  Turn out onto a piece of plastic wrap. Press dough into a disk. Refrigerate until firm, about 1 hour or overnight.

Filling Directions

• Fry bacon until browned and nearly crisp, then scoop it out to drain on a paper towel.
• Throw out bacon grease, wipe out pan, and add olive oil. 
• Add the onion and cook until soft and lightly colored (about 7 minutes). Be sure to stir the onions occasionally.
• Add the sweet potatoes, zucchini, and thyme (or rosemary) salt, and some crushed pepper. Cook for about another 7 minutes.
• While vegetables cook, whisk eggs with cream and milk. Stir in cooled onions, cheese and bacon.
• Roll dough to fit your chosen tart pan, then drape dough in pan. Neatly press dough up the sides of the pan and shape it. 
• Set it on a sheet pan. Scatter vegetable mixture and part of the bacon crumbled over the tart (reserve rest of bacon to crumble on top when finished).
• Toss the goat cheese over the vegetables. Pour in the egg mixture. Place the tart pan over a foil lined cookie sheet. 
• Bake for about 35-40 minutes or until the tart is golden brown and the filling is set. Check tart at about 30 minutes. 
•  If the tart shell is browning too much, cover the tart with foil paper for the rest of the baking time. Let tart cool before removing from tart pan or slice directly in the tart pan when warm.