In a large mixing bowl or bowl of a stand mixer, add butter and sugar and whip until fluffy and well combined. Add flour and a pinch of salt, and mix on low until the mixture resembles breadcrumbs.

Use your hands to work in the chocolate and pecans, and continue kneading gently until a loose dough has formed.

Shape dough into a log, approximately 9 inches / 23 centimeters long and about 2 inches / 5 centimeters in diameter.

Wrap log in clingfilm/plastic wrap and chill in the refrigerator until firm, at least 1 hour.

While dough chills, preheat oven to 190° C / 375° F. Line a baking sheet with a silicone baking mat, and set aside until ready to use.

Unwrap log and slice into 1/2-inch / 1.25-centimeter thick slices. Transfer to prepared baking sheet and sprinkle with coarse sea salt, pressing salt gently into the tops of the slices.

Transfer tray to the freezer and freeze for 10 minutes (or chill in the fridge for 30 minutes if your tray doesn’t fit in the freezer!)

Bake in preheated oven until shortbread is just lightly golden around the edges, about 13-15 minutes. Remove from oven and transfer to a wire rack to cool completely.

Store shortbread biscuits in an airtight container at room temperature for up to five days.