Wash the lemons under hot water, rub dry and halve them. Squeeze the juice. Clean the inside of the lemon halves and clean the pointed ends.
Soak gelatine in cold water. Measure out about 100 ml lemon juice. Squeeze the gelatine and dissolve in a small pot. Stir in 3 tbsp. lemon juice, then stir into the remaining juice. Mix yoghurt, sugar and juice and chill for about 15 minutes until it starts to gel
Whip the cream until stiff and fold into the cream. Chill the cream again for about 15 minutes until it begins to set. Then fill the cream into a piping bag with a medium-sized punched spout and squirt into the lemon halves. Chill lemons for at least 2 hours.
waiting time approx. 3 hours