For the dough
- 1 cup flour
- 1/4 teaspoon salt
- 1 teaspoon granulated sugar
- 6 tablespoons (3/4 stick) cold butter
- ¼ cup cold water or more (as needed).
For the filling
- 2 1/2 pints strawberries (about 2 pounds), steam off and cut in quarters
- 2 large stalks rhubarb (about 12 ounces), cut in 3/4 inch pieces
- 2/3 cup plus 2 tablespoon sugar
- 5 tablespoons cornstarch
- zest of 1 lemon
- 2 tablespoons cream
To make the dough, mix all dry ingredients in a mixing bowl. Cut the cold butter into 1/2-inch pieces. Add the cubed butter to the dry ingredients and, pressing the butter into the flour with fingers and using a bowl scraper (or a knife or pastry cutter), cut in the butter until the butter pieces are approximately the size of dried lentils (about 1/8 inch), working quickly to avoid melting the butter. Form a well in the mixture and pour some of the cold water into the well. Begin to combine the water into the flour/butter mixture. Be careful not to overwork the dough at this stage. Add more water as needed just until the dough comes together. Gather all the pieces of dough together, cover with plastic wrap, and refrigerate for at least 1 hour (or freeze for 20 minutes), up to overnight, to relax the gluten.
To make the filling, place strawberries and rhubarb in a mixing bowl. Add 2/3 cup sugar, cornstarch and lemon zest. Mix everything together.
To assemble the galette, preheat the oven to 400F. Roll the dough to a circle roughly 18 inches in diameter. Cut out a 16-inch circle. Slip the dough onto a baking sheet lined with parchment paper. Pour the strawberry mixture over the dough, leaving a 1 ½ inch border. Fold the dough over the filling. Brush the borders with cream and sprinkle with the additional 2 tablespoons of sugar. Bake for 40 minutes (until the bottom crust is golden brown).