Soak the gelatine in cold water.
Puree the lime juice with the mint leaves.
Boil sugar with 2 tablespoons of water until syrupy, stir in lime juice and add in 1/2 L (approximately2 cups) of water.
Squeeze out the gelatine and dissolve in the hot liquid. Mix well.
Divide the lemon zest into dessert glasses, and then portion the liquid over it. Cool in the refrigerator for about 4 hours until set.