Preheat the oven to 425ºF.

Combine the strawberries with 1 tablespoon (12 grams) sugar in a small bowl. Toss to coat, and set aside.

Combine the ¼ cup of buttermilk and the egg together in a small bowl. Beat with a fork until blended; set aside.

Add the flours, sugar, baking powder, salt, and lemon zest to a deep medium-sized bowl. Whisk to combine. Scatter the butter on top of the dry ingredients and rub together quickly with your fingers, until it forms a sandy-looking texture with some pebble-sized pieces.

Stir in the chocolate and strawberries.

Pour in the buttermilk-egg mixture, and use a wooden to swiftly stir together until it forms a clumpy looking dough. Turn the dough out onto a lightly floured counter. Knead it once or twice to give the dough a smoother appearance.

Shape the dough into a 1-inch thick circle. Use a sharp knife to cut each circle into 6 triangles (as if cutting a pizza). To make mini scones, divide the dough in half, and shape it into two 1/2-inch thick circles, and cut each one into 6 wedges for a total of 12.

Place the scones on an ungreased baking sheet. Brush with the remaining tablespoon of buttermilk and sprinkle the tops with the coarse sugar, if using. Bake for 12 to 15 minutes, until the bottoms are lightly browned and the tops are golden.

Remove from the oven and set the tray on a wire rack to cool a few minutes before serving. Leftovers may be stored in an airtight container and heated in the toaster the next day.