In a large bowl, combine the flour, sugar, and salt, and mix well. Add the dry yeast and stir to combine. Pour in the olive oil and rub the mixture between your palms until coarse crumbs form. Gradually add the orange juice and lukewarm water, kneading well after each addition. Knead the dough thoroughly for about 5 minutes until smooth and elastic.
Lightly oil a bowl and place the dough inside. Cover with plastic wrap or a towel and let it rise for 1 to 1 ½ hours, or until doubled in size.
Once the dough has risen, punch it down to deflate it and divide it into 8 equal pieces. Shape each piece into a ball and set aside. Roll out each ball into a rectangular sheet, approximately 20x24 cm in size.
For the filling, sprinkle 1/8 of the halloumi (about 62g), 1/8 of the olives (about 41g), and 10-15 mint leaves (2-3g) onto each dough sheet. Drizzle with a spoonful of olive oil. Roll up each sheet, sealing the edges with a fork to ensure they are well closed.
If desired, brush the tops of the rolls with egg wash or orange juice. Roll the filled dough in the wet sesame seeds to coat them thoroughly. Using a knife, score the top of each roll 3-4 times.
Place the rolls on a baking tray lined with non-stick greaseproof paper. Gently press each roll to slightly flatten it. Cover the tray with a towel and allow the rolls to rise for another 30 minutes.
Preheat the oven to 180°C (356°F). Bake the halloumoti in the preheated oven for 40 minutes, or until golden brown.
Allow them to cool slightly before serving. Enjoy your halloumoti with olives warm or at room temperature.