Chocolate-Dipped Pistachio Shortbread

I wanted to bake something green for Saint Patrick's Day, so I turned to the always trusty pistachio. This dough comes together so quickly, and the shortbread is buttery and crumbly with happy flecks of green sprinkled throughout. The cookies are delicious as is, but I decided to step things up because you know, Erin go Bragh and all of that, so I dipped the shortbread in melted chocolate and sprinkled with additional pistachios. Enjoy them with Irish breakfast tea and have a Happy Saint Patrick's Day!

Pistachio Shortbread
Recipe adapted from Bon Appétit

1 1/2 cups all purpose flour
1/2 cup sugar
1/2 teaspoon salt
3/4 cup (1 1/2 sticks) chilled unsalted butter, cut into 1/2-inch cubes
1/2 cup natural unsalted pistachios, lightly toasted, chopped
1 large egg yolk
3/4 teaspoon vanilla extract

Mix flour, sugar, and salt in processor. Add butter, pistachios, egg yolk, and vanilla. Pulse until moist ball forms. Transfer dough to work surface. Divide dough in half. Form each dough half into 8 x 1 1/4-inch log (if dough is too soft, chill until firm, about 30 minutes). Wrap logs in plastic; refrigerate until firm, about 4 hours. Can be made 5 days ahead; keep chilled. Preheat oven to 325°F. Slice logs into 1/4-inch-thick rounds, rolling log after every few slices to retain round shape. Place rounds on ungreased baking sheets, spacing 1 inch apart. Bake shortbread until barely golden, 16 to 18 minutes. Cool shortbread on baking sheets.

Optional: Melt 3 ounces bittersweet and 3 ounces semisweet chocolate, stir and dip cooled cookies halfway into chocolate. Finely chop 1/4 cup of pistachios and sprinkle over cookies. Let set for about an hour until chocolate hardens.