Put the yogurt in a bowl and beat well. Fold in the pomegranate seeds and chopped mint. Sweeten with a little honey or sugar, if using, then chill until ready to serve.
Peel the grapefruits, cutting off all the pith. Cut between membranes to remove segments, holding the fruit over a bowl to catch the juices.
Mix the fruit segments with the reserved juices and orange flower water and add a little honey or sugar, if using. Stir gently then decorate with a few pomegranate seeds.
Decorate the chilled yogurt with a scattering of pomegranate seeds and mint leaves, and serve with grapefruit salad.
*Variation: You can use a mixture of oranges and blood oranges, intersperesed with thin segments of lemon. Lime segments work well with the grapefruit and mandarins or tangerines could be used too. As the idea is to create a refreshing, scented salad, juicy melons and kiwi fruit would also be ideal.