Sarah's Berry Galette

For the crust

• 1 1/4 cups all-purpose flour
• 1 tablespoon sugar
• 1/4 teaspoon salt
• 1 stick cold unsalted butter, cut in cubes
• 3 to 5 tablespoons ice water

For the berries

• 3 cups mixed berries, mostly blackberry and blueberry
• 1/3 cup sugar, more if they're tart
• 1 tablespoon cornstarch, or 2 of flour
• 1 teaspoon lemon juice, a little zest if you have it
• A pinch of salt

To finish

• 1 egg, beaten, for the wash
• 1 tablespoon coarse or turbinado sugar

How it goes

1. Whisk the flour, sugar, and salt. Cut in the cold butter until you've got pea-sized pieces with a few bigger flakes left whole. Add the ice water a tablespoon at a time, just until it holds together. Don't work it. Shape it into a disk, wrap it, and chill at least an hour.
2. Toss the berries with the sugar, cornstarch, lemon, and salt. Let them sit about fifteen minutes while the dough firms up.
3. Roll the dough on a floured counter into a rough circle, about twelve inches. Move it onto a parchment-lined sheet pan. Rough edges are right.
4. Pile the berries in the center and leave yourself a two-inch border. Fold the edges up over the fruit, pleating as you go, and leave the middle open.
5. Brush the crust with the egg and scatter the coarse sugar. If it's gone soft, chill it another fifteen minutes before it bakes.
6. Bake at 400°F for 40 to 45 minutes, until the crust is deep gold and the juice bubbles thick at the edges. If it browns too fast, lay a piece of foil loosely over the top.
7. Let it cool on the pan at least twenty minutes so the bottom sets and the juices pull together. Eat it warm, standing in the kitchen, which is still the only correct way.