For the Tempura dough, mix 100 g Tempura flour, egg yolk and 1⁄4 l cold water. Do not stir too hard, the dough may be a little lumpy. Put it in the fridge, then it will be nice and crispy when baked out.
For the melon salad, mix yoghurt, crème fraîche, lemon juice and 3 tablespoons of sugar. Cut melon into slices, remove seeds and peel. Cut melon flesh into bite-sized pieces. Clean, wash, shake dry and cut into thin strips.
Mix melon and salad strips with yoghurt sauce. For the chili mayonnaise, mix mayonnaise, chili sauce and sesame oil.
Rinse shrimps, dab dry, remove dark intestine if necessary. Season with salt. Heat the oil in a wide pot to approx. 180 °C (it is hot enough as soon as bubbles rise from a long wooden skewer) or in a deep fryer.
Pull the prawns through the tempura dough with a fork, drain them a little and fry them in hot oil for 3-4 minutes, turning from time to time. Drain on kitchen paper. Arrange on the melon salad and add the chili mayonnaise.