1. In a large bowl combine flour, sugar, and salt. Cut in cold butter until mixture resembles coarse crumbs.

2. Stir in sourdough discard and add ice water one tablespoon at a time until dough just comes together. Shape into a disk, wrap and chill for at least 1 hour.

3. Toss sliced strawberries with sugar, lemon juice, cornstarch, and vanilla extract. Let rest for 10 minutes.

4. Preheat oven to 400°F (200°C). Roll chilled dough into a rough 12-inch circle on a floured surface and transfer to a parchment lined baking tray.

5. Arrange strawberry filling in center of dough, leaving a 1½-inch border. Fold edges over the filling, overlapping as needed.

6. Brush crust with beaten egg and sprinkle with coarse sugar.

7. Bake for 35-40 minutes until crust is deep golden and filling is bubbling.

8. Cool galette for 15-20 minutes before slicing. Serve warm, optionally with ice cream or whipped cream.