Thyme, Lemon, and Sea-Salt Shortbread

Ingredients

• 1 3/4 cups all-purpose flour
• 1/4 teaspoon salt
• 1 tablespoon freshly grated lemon zest, preferably organic
• 1 1/2 teaspoons finely chopped thyme leaves
• 1/2 cup unsalted butter, at room temperature
• 1 large egg, lightly beaten
• 2 large egg yolks
• 2 teaspoons water
• 1 tablespoon coarse sea salt

Directions

1. In a medium bowl, combine the flour, salt, lemon peel, and thyme. Add the butter and work it through the dry mixture with your fingertips until everything looks rough and sandy. In a separate bowl, mix the lightly beaten egg, egg yolks, and water. Set aside 1 tablespoon of that egg mixture for glazing later.
2. Make a hollow in the flour mixture, pour in the rest of the egg mixture, and bring the dough together with your hands, taking care not to knead it at this point. It should still seem somewhat crumbly. Tip it onto a lightly floured surface, then knead only a couple of times, just enough for the dough to hold. Shape it into a 1-inch-thick disc, cover it in plastic film, and chill until firm, about 1/2 hour.
3. Heat the oven to 350°F (175°C). Cover the bottom of a baking sheet with parchment paper or a nonstick baking mat. Take the dough from the refrigerator, remove the wrapping, and set it on a floured work surface. Pat it into a 6-by-5-inch rectangle, then use a rolling pin to enlarge it to a 10-by-7-inch rectangle, about 1/4 inch thick.
4. Slice the dough across the middle so you have two 5-by-7-inch sections. With a pizza wheel or a sharp paring knife, cut the dough into 1/2-inch-wide strips. Move the shortbreads carefully to the prepared baking sheet, spacing them slightly apart. Brush the tops with the saved egg mixture, scatter on a little coarse sea salt, and press the salt lightly into each piece so it adheres.
5. Bake the shortbreads until they take on a pale golden color, about 20 minutes. Move them to a rack to cool, then enjoy them warm or at room temperature. Store any leftovers in an airtight container at room temperature for up to 1 week.