1 Toast sesame seeds and fennel in a dry non-stick pan and allow to cool.
2 Drain the feta cheese and cut into about 20 cubes.
3 Rinse lemon in hot water, wipe dry and finely grate the zest. Squeeze half of lemon, (save remaining for another use) and measure 1 tablespoon juice.
4 Mix together fennel seeds, sesame seeds, lemon juice, lemon zest, oil, 1 pinch of salt and pepper to taste in a bowl. Add feta cheese cubes, and turn to coat. Cover and marinate in the refrigerator for 4 hours.
5 Rinse mint, shake dry, pluck leaves, chop finely and mix with the cheese cubes.
6 Peel the cucumber, halve lengthwise and remove the seeds with a spoon. Cut cucumber into 1 cm (approximately 1/2-inch) cubes.
7 Drain the olives and cut in half. Thread olives, cucumber and cheese on 10 skewers and serve.