Defrost strawberries in a sieve. Soak gelatine in cold water. Whip cream until stiff. Mix yoghurt and sugar. Squeeze the gelatine and dissolve in a small pot at low heat.
Stir in 2-3 tablespoons of yoghurt. Then stir into the rest of the yoghurt. Fold in the cream and chill for about 20 minutes.
Put cookies in the freezer bag. Close the bag and crumble the cookies finely. Line the mould with foil. Cut strawberries into small pieces and fold into the yoghurt cream. Pour cream into the mould. Spread biscuit crumbs on the cream.
Gently press down gently and chill for about 2 hours.
Chop the couverture and melt in a hot water bath. Leave to cool for about 15 minutes. Turn out the cream-yoghurt cream from the mould using the foil. Remove foil. Carefully pour the chocolate coating over the cream and spread.
Using a cake comb (alternatively a teaspoon handle) draw fine waves into the couverture and let them set.