Strawberry thyme galette

(Source: Baking with Julia)
3 Tablespoons sour cream (or yogurt or buttermilk)
scant 1/3 cup ice water
1 cup all-purpose flour
1/4 yellow cornmeal
1 teaspoon sugar
1 teaspoon fresh thyme leaves (optional)
1/2 teaspoon salt
7 Tablespoon cold unsalted butter, cut into 6 to 8 pieces
Stir the sour cream and the water in a small bowl and set aside.
Put the flour, cornmeal, sugar, and salt into the food processor, fitted with the metal blade. Pulse to combine.  Add the chopped butter and pulse 8 to 10 times, or until the mixture is speckled with pieces of butter that vary in size from bread crumbs to peas. As the machine runs, add the sour cream mixture and stop the processor once the dough forms soft, moist curds.
Remove the dough, divide it in half. Squish the ball down flat and wrap it in plastic and chill for at least 2 hours.

1 1/2 cups strawberries, stems removed and sliced (don't use overly ripe strawberries, as they may be too watery.)
2 Tablespoons white sugar 
1 teaspoon corn starch
1 teaspoon fresh thyme (optional)
a squeeze of lemon
Preheat the oven to 350 degrees. Line a baking sheet with parchment paper.
Clean the strawberries, remove the stems and slice them lengthwise. Place the sliced strawberries into a bowl add the sugar, lemon juice and cornstarch. Gently stir the strawberries until the sugar and cornstarch evenly cover the berries.
Roll out the galette dough into about an 11 inch circle that's about an 1/8 inch thick. Layer the berries in center the crust leaving at least one inch from the edge. Fold the edge of the dough over the strawberries. You will have to make pleats(folds) in some places. Brush the dough with a little water and sprinkle all over with 1 tsp. sugar. Bake for 30-35 minutes.
Remove from the oven and let it cool for 5-10 minutes before slicing.