Peel the melon and watermelon and remove the seeds, cut into slices and then into small cubes, about 1 cm thick.
Cut the feta into cubes and season with a little olive oil and a pinch of pepper.
Season the melon with the grated lemon zest.
With the help of a pastry ring make the tartare: put under the melon cubes, in the middle the feta cubes and finish with the watermelon cubes. Decorate with some fresh mint leaves.
Cool the tartare quickly in Freddy with the function of blast chilling for 20 minutes and serve.