Let the dough sheets rest at room temperature for about 10 minutes. Remove 4 sheets, wrap the remaining sheets well and use them for other purposes. Cut the dough sheets into squares (each approx. 10 x 10 cm).
Place 3 squares staggered on top of each other and distribute in the wells of a muffin tray (12 wells each). Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 10 minutes, take out, let cool and lift out of the tray.
Soak gelatine in cold water. Wash the lime, grate dry, grate the peel. Halve lime and squeeze juice. Mix yoghurt, sugar, lime juice and peel, except for something to decorate.
Dissolve the gelatine. Stir in 5 tablespoons of the yoghurt mass, stir into the remaining yoghurt. Whip the cream until stiff and fold in carefully. Fill the yoghurt cream into the baskets and chill for about 30 minutes.
Meanwhile, remove the seeds from the melons and use a miniature ball cutter to cut out small balls from the melon pulp. Spread melon balls on the tartlets and decorate with lime zest. Arrange the tartlets.