In a large mixing bowl, stir together the bread flour, instant yeast, sugar, and salt.
Add the warm water and 3 tablespoons of olive oil. Mix with a wooden spoon, then knead by hand on a floured counter for about 8 minutes, until the dough is smooth and springs back when poked.
Cover the bowl with a kitchen towel and let the dough rise in a warm spot for 60 minutes, or until it has doubled in size.
Punch down the dough and turn it onto a lightly floured surface. Scatter the halloumi cubes and chopped mint over the top, then fold and knead gently for 1 to 2 minutes, until they're spread through evenly.
Shape the dough into a round loaf, about 20 cm / 8 inches across, and place it on a parchment-lined sheet pan (33 x 46 cm / 13 x 18 inch).
Cover loosely and let the loaf rise again for 15 to 20 minutes, until slightly puffed.
Heat the oven to 200 C / 390 F while the dough finishes its second rise.
Brush the top of the loaf with the remaining 1 tablespoon of olive oil and sprinkle with sesame seeds, if using.
Bake for 28 to 32 minutes, until the crust is deep golden brown and the loaf sounds hollow when tapped on the bottom. An instant-read thermometer inserted into the center should read 200 F / 93 C.
Let the bread cool on the pan for 10 minutes before slicing into 8 wedges. Serve warm.