Zucchini and goat cheese galette

This recipe is adapted from a very delicious version made by Smitten Kitchen - I've substituted goat cheese for ricotta and used lemon basil to add a bit of extra zing.  In any case, this free form tart is packed full of flavor and tastes great warm or cold.

Ingredients

Pastry

1.25 c flour
1/4 t salt
8 T unsalted butter,
1/4 c sour cream/creme fraiche
2 t lemon juice
1/4 c ice water
1 egg yolk for glaze

Filling

1 large (or 2 small) zucchinis, sliced into 1/4" rounds
1 T olive oil
1 clove garlic, minced
1/2 c fresh goat cheese (I mixed some goat cheese with sour creme to get a more spreadable texture)
1/2 c grated parmesian
1/2 c shredded mozzarella (or similarly soft cheese)
1 T slivered basil leaves (use lemon basil if you can find it!)

Instructions

1) Combine salt and flour in a large bowl.  Sprinkle small chunks of butter over mixture, and blend with a pastry cutter until the mixture resembles very coarse sand.  (You can also do this in a food processor, using short 1/2 second bursts - just don't overmix!)
2) In a small bowl, combine sour cream, lemon juice, and water.
3) Add liquid to flour mix, and mix gently with fingertips or a spoon, until the dough is in large lumps.  Try not to overmix, as you will bread up the butter globules and the pastry will be tough not flaky.  If your dough is too wet, add a few T of flour.
4) Cover pastry with plastic wrap and place in the freezer for 15 minutes, until dough is cold and firm (but definitely not frozen).
5) Combine oil and garlic in a small bowl and set aside.
6) In a medium bowl, mix goat cheese, parmesian, mozzarella, basil, and 1 t of garlicky oil.  Set aside.
7) After the dough is chilled, preheat oven to 200C.  On a flour work surface, roll the dough into a 12 inch round (either with your fingers or a rolling pin).  For extra flaky dough, fold the dough over itself several times.
8) Transfer dough round to a parchment-lined baking tray.  Spread cheese mixture evenly over middle of dough, leaving a 2" border.
9) Arrange zucchini in concentric circles, overlapping slightly, and starting at the outside edge.
10) Drizzle with garlic olive oil, and fold dough over the filling, pleating the edge to make it fit.
11) Mix egg yolk with 1 T water, and brush over dough.
12) Bake galette 30-40 minutes, until crust is firm and gold brown, and zucchini is slightly wilted.