Chop the chocolate into small pieces and the mint leaves roughly into large pieces. Mix all the ingredients marked ＊ and set aside.

Bring the butter to room temperature, add the granulated sugar and salt, and mix well until the mixture turns white.

Mix the egg and milk, divide into 3 batches, add to the stirred butter and mix it all together.

Add the ＊ ingredients to the bowl and mix in. Then add the chocolate and mint leaves and mix it all together.

Divide the dough into 3 sticks, then wrap each and let rest in the freezer for 1.5 hours until they have chilled and hardened.

Sprinkle granulated sugar, cut into 7 mm cookies and bake for 13-15 minutes in a 175°C (340°F) oven.

Transfer to a rack, and when they are cooled, they are done.