Chocolate Walnut Cookies
For the cookies: In a bowl, beat the egg whites with the salt until stiff. Beat in the sugar. Continue beating while adding the flour gradually. Stir in the ground walnuts. Stir in the butter until a smooth dough is formed.
Place the dough in a piping bag fitted with a round tip. Pipe small dots of dough on a parchment-lined baking sheet.
Bake in a 180°C (approximately 350°F) oven for 12 minutes. Remove and allow to cool.
For decorating: Chop the couverture and place in a bowl. Set over a pot of simmering water and stir until melted. Spread the chocolate on half the cookies and sandwich with the remaining cookies. Spread chocolate on top of the cookies and garnish with a walnut half.